Efficacy of hybrid adsorption/membrane pretreatment for low pressure membrane.

Fouling by natural organic matter (NOM) is a major obstacle when water from natural sources is treated using low-pressure membranes. Prior research by our group has demonstrated that passing natural water through a thin, pre-deposited layer of heated aluminum oxide particles (HAOPs) can remove substantial amounts of NOM from the feed and thereby reduce the fouling rate of downstream membranes. The work reported here explored the technical efficacy of such a pretreatment process under more challenging (and therefore realistic) conditions than reported earlier. Several analytical techniques were applied to the feed and permeate in an attempt to identify the key fouling components. The results demonstrate that a HAOPs layer can be pre-deposited on a stainless steel mesh and then be readily washed off at the end of a filtration cycle with very little irreversible fouling due to residual NOM or HAOPs left on the mesh. In addition, the pretreatment step removes enough foulant to allow a downstream UF membrane to operate at significantly higher fluxes than when conventional pretreatment is applied. HAOPs pretreatment also reduced the formation of chlorinated and brominated trihalomethanes (THM4) by more than 67% and of haloacetic acids (HAA9) by 64%-88% in simulated distribution system (SDS) tests.

Nitrogen compounds in drain sewage after constructed wetlands.

Constructed wetlands, commonly known as ground filters, are well suited mostly for wastewater treatment in areas with no central sewage system. The basic difficulty with exploitation of constructed wetlands is connected with irregular hydraulic overload of its surface. However, irregular wastewater inflow can be reduced by cyclical irrigation which increases efficiency. The unquestionable advantage of the constructed wetlands is inexpensive construction and exploitation as well as low energy consumption. The constructed wetlands also fit very well in surrounding area. The investigation concerned the analysis of two constructed wetlands which are composed of mechanical separation (septic tank) and a filter bed with subsurface flow. The research has been undertaken in a period from July to December 2008, with regard to concentration distribution of nitrogen compounds in municipal sewage after constructed wetlands. The preliminary investigation on constructed wetland which has been exploited for 10 years showed variable removal efficiency of nitrogen compounds. The continuation of the research can indicate the efficiency of wastewater treatment in summer and winter season.

Advantages of exercise echocardiography in comparison to dobutamine echocardiography in the diagnosis of coronary artery disease in hypertensive subjects.

OBJECTIVE: The aim of the study was to compare the efficacy and safety of two stress echocardiography methods, exercise and dobutamine, in the diagnosis of coronary artery disease in hypertensive patients with angina. PATIENTS AND METHODS: A total of 197 treated hypertensive patients, age 53 +/- 9 years (65 women) with no history of myocardial infarction referred for coronary angiography were prospectively investigated with exercise electrocardiography (ECG), exercise and dobutamine echocardiography. RESULTS: Sensitivity of the exercise ECG, exercise echocardiography and dobutamine echocardiography did not differ (77%, 82% and 75%). Negative predictive value of exercise ECG was significantly lower than exercise echocardiography (64% vs 79%, P < 0.01). Specificity and positive predictive value of exercise ECG were markedly lower than exercise and dobutamine echocardiography (57%, 96%, 98% and 72%, 97%, 98%, P < 0.0001 for both stress echocardiography vs ECG). Specificity and sensitivity of diagnostic methods were not influenced by the presence of echocardiographic left ventricular hypertrophy. Dobutamine infusion in comparison to exercise was more often associated with substantial arterial blood pressure rise or fall (7% vs 2%, P < 0.05) and with simple ventricular ectopy (15,7% vs 6,1%, P < 0.05). CONCLUSIONS: In hypertensive patients with the symptoms of angina, both stress echo methods are significantly more specific than the exercise ECG test. Maximal exercise is associated with less frequent side effects than infusion of dobutamine, so exercise echocardiography may be preferred in the diagnosis of angina in hypertensive patients.

[Taking history in diagnosing coronary artery disease in the 21st century--wasting time or a valuable diagnostic tool?]. / Badanie podmiotowe w rozpoznawaniu choroby wiencowej w XXI wieku--strata czasu czy tez moze wartosciowa metoda diagnostyczna?

UNLABELLED: The relation of chest pain characteristics and other features of the history of disease to coronary angiograms was assessed in 551 patients with chest pain regarded as definite or probable stable angina pectoris. A standardised questionnaire was used to record demographic details and chest pain characteristics of interviewed patients. The differentiation between typical, atypical or nonanginal pain was based on classification proposed by Diamond. The indications for catheterization in each patient were determined at the discretion of the attending physician. All patients underwent diagnostic coronary angiography (clinically important coronary artery disease was defined as > 50 per cent narrowing of the diameter of at least one major vessel or > or = 50 per cent of the left main coronary artery). CONCLUSION: Chest pain characteristics remains an effective tool for estimating probability of coronary artery disease.

Hyperinsulinaemia and decreased plasma levels of dehydroepiandrosterone sulfate in premenopausal women with coronary heart disease.

OBJECTIVES: The purpose of the study was to establish plasma levels of insulin, ovarian sex hormones and dehydroepiandrosterone sulfate (DHEA-S) and to evaluate their correlations with lipids in premenopausal women with angiographically demonstrated coronary stenosis. DESIGN: Differences in plasma levels of insulin, ovarian sex hormones, DHEA-S and lipids between groups were compared by analysis of variance. SETTING: From January 1993 until December 1993 patients were diagnosed in the Outpatient Clinic of the Department of Endocrinology Medical Centre for Postgraduate Education, Warsaw. SUBJECTS: Premenopausal women with normal oral glucose tolerance test (OGTT) results, with and without coronary stenosis were studied: 21 women after acute myocardial infarction with angiographically demonstrated coronary stenosis (women with CHD), and 14 women with chest pain, a positive exercise test without significant changes of coronary arteries on coronarography (women with normal coronarography, NC). The control group consisted of nine, healthy women with no risk factors for CHD. MAIN OUTCOME MEASURES: In premenopausal women with CHD, the decreased plasma level of DHEA-S and hyperinsulinaemia were anticipated. RESULTS: In women with CHD, the plasma levels of DHEA-S (926.5 +/- 83 ng mL-1) were significantly lower than those in women with NC (1375.7 +/- 181 ng mL-1) and in healthy controls (1984 +/- 127 ng mL-1), P < 0.02 and P < 0.001, respectively. The fasting insulin and insulin response to an OGTT in women with CHD and with NC was higher than in healthy subjects. A significant decrease of high-density lipoprotein (HDL) cholesterol, HDL-2 cholesterol and apolipoprotein A-I, and an increase of total cholesterol, low-density lipoprotein cholesterol C and apolipoprotein B levels in women with CHD compared to healthy controls were observed. A negative correlation between fasting insulin and the plasma levels of DHEA-S was established. CONCLUSION: In premenopausal women, hyperinsulinaemia and decreased DHEA-S levels may contribute to the development of coronary atherosclerosis.

[Sensitivity of exercise echocardiography, electrocardiographic exercise test and 24-hour ekg monitoring in diagnosing and evaluating the efficacy of coronary disease treatment]. / Znaczenie wysilkowej echokardiografii, elektrokardiograficznej proby wysilkowej i 24-godzinnego monitorowania EKG w rozpoznaniu i ocenie skutecznosci leczenia choroby wiencowej.

To test the sensitivity and specificity of noninvasive tests for detecting myocardial ischemia, 78 patients undergoing cardiac catheterisation for suspected coronary artery disease (CAD) were studied in prospective blinded manner with exercise echocardiography (EE), ecg stress test (ET) and 24-hour Holter monitoring for analysis of ST-segment changes (HM). All noninvasive tests were repeated after one year follow-up period. Exercise was performed in a supine position using a bicycle ergometer. Real time 2-DE examinations were performed in the left lateral position: at rest, at the peak of exercise and immediately after exercise testing. The sensitivity and specificity of EE, ET and HM for detection of CAD were: 76%, 92%; 90%, 48%; and 80%, 71% respectively. In a group of 48 pts with the narrowing of coronary artery (CA) < 50%, the follow-up EE was negative in 45. In a group of 30 pts with significant narrowing of CA, 10 were asymptomatic within one year after PTCA or CABG; in 9 of them the follow-up EE as well as ET were negative. HM less correlated with clinical course in asymptomatic subjects: in 4 patients it was negative and in 6 - positive. The reminding 20 patients with CAD treated medically, with PTCA or CABG were symptomatic after one year. The follow-up EE, ET and HM studies were positive in 17, 19 and 17 cases respectively. We conclude that sensitivity of EE in diagnosis of CAD is comparable to ET and HM, but its specificity is higher.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of amiodarone and disopyramide on the results of electrocardiographic exercise stress testing in patients with coronary disease]. / Wplyw amiodaronu i dizopiramidu na wyniki elektrokardiograficznej próby wysilkowej u osób z choroba niedokrwienna serca.

The study was designed to assess the influences of antiarrhythmic therapy on exercise tolerance in patients with coronary artery disease and ventricular arrhythmias. Subjects for this study were subdivided into 3 groups: group I - 46 patients treated with amiodarone 1,200 mg daily during 10 days and 200-600 mg daily within next days, group II - 79 patients receiving disopyramide 300-600 mg daily, group III - 129 patients with combined administration of disopyramide 300-600 mg daily and propranolol 30-240 mg daily. propranolol 30-240 mg daily. Submaximal exercise stress testing was performed in each patient before treatment and after the medication for 4 weeks (group I) and for 2 weeks (groups II, III). The following parameters have been evaluated: maximal archived workload, maximal heart rate blood pressure response, double product (maximal heart rate x maximal systolic blood pressure), reasons for ending the test (target heart rate, typical angina, exhaustion, ST-segment depression greater than or equal to 2 mm, occurrence of ventricular arrhythmia, blood pressure greater than 250/120 mm Hg, significant drop in systolic pressure). Positive result of exercise ECG was defined: horizontal or down-sloping ST-segment depression greater than or equal to 1 mm and/or typical chest pain. The data from the first and second tests were estimated for significance of differences between the mean values with following results: 1) maximal achieved workload, 86 +/- 46 and 103 +/- 49 W (p less than 0.02) in group I; 101 +/- 64 and 106 +/- 50 W (NS) in group II; 107 +/- 55 and 119 +/- 54 W, W (p less than 0.01) in group III.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum reverse triiodothyronine (3,3',5'-L-triiodothyronine) in chronic renal failure.

Serum reverse triiodothyronine (reverse T3), triiodothyronine (T3), thyroxine (T4) and thyrotropin (TSH) concentrations were determined by radioimmunoassay in end-stage chronic renal failure, hypothyroidism and control subjects. In advanced chronic renal failure serum reverse T3 was normal or elevated and serum T3 concentrations were frequently, and serum T4 occasionally, lowered. Serum TSH was normal even where serum T3 and T4 concentrations were low. Normal or elevated serum reverse T3 associated with normal serum TSH in chronic renal failure clearly differentiates this disease from primary hypothyroidism in which low serum reverse T3 and high serum TSH are constantly found.