[Urbanization--a factor that increases the risk for health].

The negative impact of urbanization on public health is obvious. However; due to the comprehensiveness and polymorphicity of its manifestations there are not established criteria for them. Health risk methodology allows, in principle, to obtain quantitative indices of the separate results of the impact on the health status of the citizens of metropolis that can be extremely effective in this area. The total cross-media riskfrom traffic pollution, drinking water quality, open ponds, noise, etc. permits to use of hygiene criteria in urban planning, insurance, taxation, etc.

[New methodical approaches in the projection of zones of sanitary protection of water sources].

In the projection of sanitary protection zones of water sources it is extremely important to determine the specific boundaries of the established zones of sanitary protection due to the solution of property issues and responsibilities. In the paper projection of data with account of required scaling it is not possible to do. In this case, the use of geographic information systems is appropriate and useful. In addition there is necessary an adjustment of the existing sanitary calculations in relation to zones of sanitary protection of water sources in the part of specification of the order of approval of projects of sanitary protection zones and organization of the control for their implementation.

[Conceptual model for assessment and management of human risk from transport pollution].

The existing methodology for human health risk assessment allows one to appreciably study cause-and-effect relationships between environmental factors and human health. Risk management is a logic continuation of the assessment of human health risk and it is aimed at substantiating the choice of decisions that are best in a specific situation to eliminate or minimize it, to make follow-up monitoring of exposures and a risk, to evaluate the efficiency of health-improving measures and to correct the latter. Risk management involves technical, technological, organizational, social, legal, economic, normative, political, and other decisions made on the conclusions and estimates obtained when characterizing the risk.

Retention of conditioning agent hyaluronan on hydrogel contact lenses.

Hyaluronan, a member of the glycosaminoglycan family of biological polysaccharides, is a high-molecular-weight disaccharide polymer found throughout the human body, particularly in the eye. Bausch+Lomb Biotrue™ multi-purpose solution contains hyaluronan as a lens conditioning agent. The retention of hyaluronan from Biotrue multi-purpose solution to a variety of hydrogel contact lenses was evaluated over time. Fluorescein-tagged hyaluronan was allowed to adhere to lenses, which were then rinsed with balanced salt solution at a rate comparable to human tear secretion. Results demonstrated that hyaluronan was released slowly throughout the rinse period. The chemistry of the lens materials appeared to contribute to the hyaluronan retention capacity for each lens type. The results suggest that a multi-purpose solution containing hyaluronan has the potential to provide lens conditioning regardless of the hydrogel contact lens used.

Candesartan cilexetil and renal hemodynamics in hypertensive patients.

This randomized, double-blind, placebo-controlled crossover study evaluated the effects of the angiotensin II type 1 (AT1)-receptor blocker candesartan cilexetil on renal blood perfusion and glomerular filtration in patients with primary hypertension with diastolic blood pressure of 100 to 114 mm Hg. After a 4-week placebo run-in period, patients were randomized to receive either 16 mg candesartan cilexetil or placebo once daily for 6 weeks, after which they were switched to the alternative treatment. At the end of each period, 24 h after the last dose, renal assessments were made and the plasma renin activity, plasma concentrations of angiotensin II, aldosterone, and catecholamines were measured. Compared with placebo, candesartan cilexetil significantly reduced mean arterial pressure, by 8 mm Hg (95% confidence interval [CI], 3;12). Renal vascular resistance was significantly reduced by 0.03 mm Hg/mL min(-1) (95% CI, 0.01; 0.06). There was a small nonsignificant increase in renal plasma flow. The filtration fraction fell slightly from 0.24 to 0.22 (95% CI, -0.00, 0.04). As expected, angiotensin II concentrations and plasma renin activity were increased and the aldosterone concentrations were reduced. Catecholamine concentrations were unaffected. In conclusion, 6 weeks' treatment with 16 mg candesartan cilexetil once daily induced a reduction of renal vascular resistance and a trend toward increased renal plasma flow despite a reduction in mean arterial pressure. Because the glomerular filtration rate was maintained the filtration fraction was reduced, indicating a decreased glomerular capillary pressure.

Deletion 5q31 in patients with stable, melphalan-treated multiple myeloma.

The risk of myelodysplastic syndrome (MDS) or acute myeloblastic leukemia (AML) in patients with multiple myeloma has been estimated to be 10-20% after 10 years. Most myeloma patients develop MDS/AML after 3-4 years of treatment with alkylating agents, mainly melphalan; chromosomes 5 and 7 are most frequently involved. We studied 14 patients with myeloma by fluorescence in situ hybridization (FISH) with a probe to 5q31 (the critical area of deletion on chromosome 5) to verify whether deletion of 5q31 occurs during the course of stable, uncomplicated myeloma, and to assess the clinical importance of this abnormality. We found 2 patients (14%) with deletion of 5q31 in 30-40% of their peripheral white blood cells. One patient with this deletion received a high cumulative amount of melphalan, and the other patient was treated with multiple alkylating agents, including melphalan. In these patients, no clinical or laboratory evidence of transformation occurred 14 and 12 months after the finding of the aberration. These findings suggest that 5q-may occur months prior to the overt development of (t)-MDS/AML, and raise important concerns regarding the management of patients with this and similar aberrations, including modification of treatment and performance of cytogenetic evaluation prior to autologous or PSC transplantation. The clinical and biological implications of these findings should be evaluated in larger clinical and laboratory studies.

Candesartan cilexetil in hypertension: effects of six weeks' treatment on haemodynamics, baroreceptor sensitivity and the renin-angiotensin-aldosterone system.

The effects of the angiotensin II receptor blocker candesartan cilexetil on systemic and forearm haemodynamics and baroreceptor sensitivity were evaluated in this randomized, placebo-controlled, double-blind, crossover study. After a 4-week placebo run-in period, 22 patients with essential hypertension (diastolic blood pressure 100-114 mmHg) were randomized to receive either candesartan cilexetil 16 mg or placebo once daily for 6 weeks. At the end of each period, 24 h after the last dose, invasive haemodynamic assessments were performed. Simultaneously, the plasma renin activity and plasma concentrations of angiotensin II, aldosterone and catecholamines were measured. Compared to placebo, candesartan cilexetil significantly reduced mean arterial pressure by 8 mmHg (95% CI: 2.6; 12.3), while cardiac output, stroke volume and heart rate were unchanged. Forearm vascular resistance was reduced by 1 mmHg x ml(-1) x L x min (CI: 0.3; 2.3). The baroreceptor sensitivity was not influenced, but a change in the set-point was noted. Plasma renin activity and angiotensin II concentrations were increased, while the aldosterone concentration was significantly reduced. Plasma catecholamine concentrations were unaffected. In conclusion, 6 weeks' treatment with candesartan cilexetil 16 mg o.d. induced systemic and forearm vasodilatation and a reduction in blood pressure without compromising cardiac performance. The plasma concentration of aldosterone was reduced.

Acute effects of candesartan cilexetil (the new angiotensin II antagonist) on systemic and renal haemodynamics in hypertensive patients.

OBJECTIVES: This study was performed to assess the acute effects of the new angiotensin II antagonist, candesartan cilexetil, on systemic and renal haemodynamics in patients with sustained essential hypertension [diastolic blood pressure (DBP) 95-114 mmHg]. METHODS: After 4 weeks of placebo treatment, systemic and renal haemodynamics were investigated in 17 patients with a mean age of 62 years and a mean systolic and diastolic blood pressure of 170/98 mmHg, just before (baseline) and for 4 h after administration of a single oral dose of candesartan cilexetil, 16 mg. Plasma concentrations of candesartan (the active compound formed from the pro-drug candesartan cilexetil), angiotensin II (Ang II), as well as plasma renin activity (PRA), were measured before and after dosing. RESULTS: At 2, 3 h and 4 h after dosing with candesartan cilexetil, systolic blood pressure (SBP) and DBP, as well as mean arterial pressure (MAP), were significantly lower than at baseline. The mean reduction in MAP 4 h after dosing was 8.8 mmHg (-6.5%). This effect was due to a fall in total peripheral resistance (TPR), while heart rate (HR), stroke volume (SV) and cardiac output (CO) were virtually unchanged. After 4 h there was a marked reduction in renal vascular resistance (RVR) of 0.0273 mmHg x ml(-1) x min (-16%), resulting in an increased renal plasma flow of 64.9 ml x min(-1) (14%). The glomerular filtration rate was increased by 7.75 ml x min(-1) (8%), and the filtration fraction (FF) was not significantly changed. There was no apparent relationship between the changes observed in systemic and renal haemodynamic variables and plasma concentrations of candesartan. Plasma renin activity increased over the study period, but in general the patients had low PRA. Changes in plasma concentrations of angiotensin II were inconsistent between patients. CONCLUSION: A single oral tablet of candesartan cilexetil, 16 mg, induced systemic and renal arterial vasodilatation and blood pressure reduction, without compromising renal perfusion or filtration or affecting cardiac performance. Plasma renin activity which was low in general, increased over the study period, but changes in plasma concentrations of angiotensin II were inconsistent.