The effect of occupational lead exposure on lipid peroxidation, protein carbonylation, and plasma viscosity.

The aim of the study was to investigate the influence of occupational lead (Pb) exposure on lipid peroxidation, protein carbonylation, and plasma viscosity in workers. The examined group included 283 healthy male employees of manufacturing facilities using zinc and Pb. The mean blood concentrations of Pb and zinc protoporphyrin as well as the mean urine δ-aminolevulinic acid levels were used as markers of exposure for the examined group. Taking into account the obtained mean values of blood lead level, the examined group was divided into three subgroups. When comparing the control group with the subgroups, Pb exposure markers were significantly elevated in all the three subgroups. Concentrations of conjugated dienes (CD), lipid hydroperoxides, malondialdehyde (MDA), and protein carbonyl groups were also significantly increased. Conversely, the levels of total protein and protein sulfhydryls were significantly decreased in the subgroups compared with the controls. The plasma viscosity was significantly elevated in the subgroups. A dose-response between Pb levels and plasma viscosity was not observed. Pb supposedly elevates MDA and CD in a dose-dependent manner. In conclusion, occupational Pb exposure induces oxidative stress that results in lipid and protein damage. Moreover, Pb-induced oxidative stress is likely the primary factor that elevates plasma viscosity, despite decreased protein levels.

Influence of rheological factors on the development of primary open angle glaucoma.

The aim of this study was to compare our non published investigation on the effect of rheological factors on the development of primary open angle glaucoma (POAG)--to literature data. POAG is a chronic eye disease characterised by a slowly progressive neuropathy of the optic nerve with typical anatomical and functional lesions and is associated with specific visual field defects.

Influence of hemorheological factors on the development of retinal vein occlusion.

OBJECTIVE: The aim of this article was to present the influence of hemorheological factors on appearance of Retinal Vein Occlusion (RVO). Article explains which factors predispose to the occurrence of RVO. STUDY SELECTION: Data presented in the article were collected from both review articles and research articles as well as other sources concerning hemorheology, pharmacology and ophthalmology. RESULTS: Appearance of RVO is connected with blood viscosity and hemorheological parametres like aggregation of red blood cells, deformability of red blood cells, fibrinogen concentrations and haematocrit, and platelet activity. In the pathogenesis of retinal vein occlusion other risk factors were also indicated: age, systemic diseases and smoking. Such correlation has been indicated in numerous researches which were conducted over the last years. RVO is usually accompanied by macular oedema. RVO may successfully be treated using intravitreal dexamethasone implant. CONCLUSION: Quick diagnosis and therapy create a possibility for successful treatment. Corticosteroid positive influence on visual acuity improvement has been indicted in two randomized, double-blind controlled studies - CRUISE and BRAVO. In both studies, the improvement of vision has been accompanied by a significant reduction of oedema in the vicinity of macula, reflected in the central retinal thickness.

The effects of weight loss surgery on blood rheology in severely obese patients.

BACKGROUND: The effects of dieting on blood rheology in obese individuals suggest that improving the rheologic profiles depends on the amount of weight lost and its long-term maintenance. The aim of this study was to evaluate the effects of weight loss after surgery on blood rheology at 12-month follow-up. METHODS: We studied 38 obese patients who underwent laparoscopic weight loss surgery, 22 of whom had sleeve gastrectomy (SG) and 16 of whom had gastric banding (LAGB). We evaluated rheologic parameters such as blood viscosity, plasma viscosity, and erythrocyte deformability (as measured by elongation index [EI]) preoperatively and 12 months after surgery. RESULTS: Whole blood viscosity at 150 s(-1) shear rate (P<.01) and 300 s(-1) shear rate (P<.05), blood viscosity corrected to a standard hematocrit at both shear rates (P<.0005 and P<.005, respectively), and plasma viscosity (P<.005) were significantly reduced after surgery. EI evaluated at different shear stresses (18.49-60.03 Pa) decreased (P<.005) 12 months after surgery. There were significantly decreased EI and blood viscosity corrected to a standard hematocrit after SG (P<.005 and P<.05) and LAGB (P = .0621 and P<.05), but plasma viscosity significantly decreased only after SG (P<.005). Blood viscosity at both shear rates correlated with plasma viscosity (r = .51, P<.005 and r = .5, P<.005). Plasma viscosity correlated positively with body mass index (r = .57; P<.0005) and negatively with percentage of excess weight lost (r = -.56; P< .005). CONCLUSIONS: This study found that weight loss after bariatric surgery induced improvement in blood rheology in obese patients at 12 months after surgery. The increased red blood cell rigidity after surgery requires further study because the physiologic importance of this change has not yet been established.

Impact of weight loss due to sleeve gastrectomy on shear stress of the femoral vein in morbid obesity.

BACKGROUND: Studies have shown that obesity is associated with venous flow disturbances that lead to changes of the biomechanical forces on the venous wall known as shear stress. We hypothesized that weight loss due to bariatric surgery affects the venous hemodynamics and biomechanical forces on the venous wall. The aim of this study was to evaluate the effects of laparoscopic sleeve gastrectomy (LSG) on the wall shear stress (WSS) and the venous hemodynamics of the femoral vein. METHODS: We studied ten morbidly obese patients who underwent LSG. We investigated venous hemodynamics before, 6 and 12 months after LSG. The femoral vein diameter, cross-sectional area, peak (PeakV) and maximum (TAmax) velocities, WSS, and shear rate (SR) were assessed. RESULTS: PeakV and TAmax were significantly lower in the obese patients compared with the control group. WSS and SR were significantly lower in the obese patients compared with the control subjects. Venous hemodynamic parameters increased in the postoperative period at baseline compared with 12 months after surgery: PeakV increased from 17.53 (14.25-20.01) cm/s to 25.1 (20.9-30.1) cm/s (P = 0.04) and the TAmax from 12.97 (11.51-14.6) cm/s to 18.46 (13.24-24.13) cm/s (P = 0.057). WSS significantly increased from 0.21 (0.19-0.23) Pa at baseline to 0.31 (0.23-0.52) Pa 12 months after surgery (P = 0.031). SR also significantly increased from 47.92 (43.93-58.55) s(-1) at baseline to 76.81 (54.04-109.5) s(-1) 12 months after surgery (P = 0.02). CONCLUSIONS: This study showed that weight loss due to LSG significantly changes the biomechanical forces on the femoral vein generated by blood flow.

The impacts of super obesity versus morbid obesity on red blood cell aggregation and deformability among patients qualified for bariatric surgery.

The aim of this study was to evaluate the effects of the obesity degree on red blood cell aggregation and deformability. We studied 56 obese patients before weight loss surgery who were divided into two groups: morbid obesity and super obesity. The aggregation and deformability of RBCs were evaluated using a Laser-assisted Optical Rotational Cell Analyzer (Mechatronics, the Netherlands). The following parameters specific to the aggregation process were estimated: aggregation index (AI), aggregation half-time (t1/2) and threshold shear rate (γthr). RBC deformability was expressed as erythrocyte elongation (EI), which was measured at 18.49 Pa and 30.2 Pa shear stresses. Super obese patients presented significantly higher AI (P < 0.05) and γthr (P < 0.05) and significantly lower t1/2 (P < 0.05) compared with morbidly obese individuals. Multivariate analyses showed that fibrinogen (ß 0.46, P < 0.01 and ß 0.98, P < 0.01) and hematocrit (ß 0.38, P < 0.05 and ß 1.01, P < 0.01) independently predicted the AI in morbidly obese and super obese patients. Fibrinogen (ß -0.4, P < 0.05 and ß -0.91, P < 0.05) and hematocrit (ß -0.38, P < 0.05 and ß -1.11, P < 0.01) were also independent predictors of the t1/2 in both obese groups. The triglyceride level (ß 0.32, P < 0.05) was an independent predictor of the t1/2 in the morbidly obese group. No differences in EI were observed between obese subjects. Multivariate analyses showed that the triglyceride level independently predicted EI at 18.49 Pa (ß -0.42, P < 0.05 and ß -0.53, P < 0.05) and 30.2 Pa (ß -0.44, P < 0.01 and ß -0.49, P < 0.05) in both obese groups. This study indicated that the obesity degree of patients who qualify for bariatric surgery affects RBC aggregation properties, but it does not indicate the reasons for this difference. Further studies are needed to determine factors associated with hyperaggregation in super obesity.

The effect of lead-induced oxidative stress on blood viscosity and rheological properties of erythrocytes in lead exposed humans.

Lead-induced oxidative stress has been identified as the essential factor in lead poisoning pathogenesis. Therefore, the present study examined the association between occupational lead exposure and blood rheological parameters with respect to malondialdehyde (a lipid peroxidation product), lipofuscin, and glutathione concentrations in erythrocytes. The examined group included 283 healthy male employees of lead-zinc works. In brief, 129 workers were classified as the low-exposure group, while the high-exposure group was composed of 154 workers. The mean blood levels of lead and zinc-protoporphyrin and the mean urine concentrations of delta-aminolevulinic acid were used as exposure markers. The control group consisted of 73 healthy male administrative workers. Whole blood viscosity was elevated in both exposure subgroups compared with the control group. Erythrocyte aggregability increased significantly; although the increase was greater in the low exposure group. Erythrocyte deformability decreased in both subgroups. The levels of malondialdehyde and lipofuscin were significantly elevated, whereas the glutathione content decreased. In conclusion, occupational exposure to lead may induce oxidative stress in erythrocytes. This stress elevates whole blood viscosity and disturbs erythrocyte aggregability and deformability. There is a dose-effect relationship between lead levels and blood rheological parameters.

Association between hemorheological alteration and clinical diagnosis of metabolic syndrome among patients qualified for bariatric surgery.

This study presents the association between metabolic syndrome and hemorheological parameters among obese patients qualified for bariatric surgery. We studied 73 morbidly obese patients who were qualified for bariatric surgery. Blood and plasma viscosity measurements were performed using a cone-plate viscometer (Brookfield DV-II). RBC aggregation was measured using the Laser-assisted Optical Rotational Cell Analyser (LORCA). The following parameters for the aggregation process were estimated: aggregation index (AI), amplitude (AMP), aggregation half-time (t1/2), threshold shear rate (γthr), the fast (Tfast) and the slow (Tslow) component. Metabolic syndrome was defined according to the Adult Treatment Panel III and International Diabetes Federation criteria. The obese presented differences in all rheological properties compared to control, regardless of clinical diagnosis of metabolic syndrome, except that whole blood viscosity was higher only in the obese metabolic syndrome group. No differences among the obese with and without metabolic syndrome were observed except in hematocrit. Whole blood viscosity and corrected blood viscosity correlated positively with WHR and BMI. AI, γthr, Tslow correlated positively with BMI, WHR, total cholesterol level and low-density lipoproteins. Negative correlation presented t1/2 with BMI, WHR, fibrinogen, total cholesterol level and low-density lipoproteins. The study showed that morbid obesity is associated with hemorheological disturbances independently of clinical diagnosis of metabolic syndrome.

Shear stress and flow dynamics of the femoral vein among obese patients who qualify for bariatric surgery.

The aim of this study was to evaluate the effects of obesity on wall shear stress and its relationship to erythrocyte aggregation. We studied 35 morbidly obese patients who were qualified for bariatric surgery. The control group consisted of 20 non-obese people. Blood rheological measurements were performed using the Laser-assisted Optical Rotational Cell Analyzer (Mechatronics, the Netherlands) and a cone-plate viscometer (Brookfield DV-II). The venous flow dynamics were assessed using a duplex ultrasound. The shear rate was estimated from the measured blood flow velocity and the diameter of the femoral vein. Venous wall shear stress was calculated from the whole blood viscosity and the shear rate. The shear rate (P < 0.005) and the venous wall shear stress (P < 0.05) were significantly lower in obese patients compared with the controls. The aggregation index (P < 0.001), syllectogram amplitude - AMP (P < 0.05) and Tslow (P < 0.001) were significantly higher in the obese patients; the aggregation half-time (P < 0.001) and Tfast (P < 0.001) were decreased compared with the control group. Multivariate regression analyses found waist circumference (ß -0.31, P < 0.05), thigh circumference (ß 0.33, P < 0.05) and Tslow (ß -0.47, P < 0.005) to be variables that independently influenced the shear rate. Nevertheless, the AMP (ß 0.34, P < 0.05) and Tslow (ß -0.47, P < 0.01) were independent predictors that influenced the wall shear stress. This study indicates that there is a relationship between wall shear stress in the femoral vein and the rheological impairment of the RBC among obese patients, but further studies are necessary to confirm this suggestion.

Results of cataract surgery in the very elderly population.

AIM: The aim of our study was to retrospectively evaluate the effectiveness and safety of cataract surgery and intraocular lens implantation (IOL) for patients aged 90 years or older, whom we define as "very elderly." METHODS: The study involved a total number of 122 patients (122 eyes) with senile cataracts. The mean age of patients was 91.2 ± 2.3 years (range 90-100 years old). Phacoemulsification (phaco) was done on 113 of 122 eyes, and 9 of 122 eyes had extracapsular cataract extraction (ECCE). Postoperative visual acuity and intraocular pressure (IOP) were analyzed on the first postoperative day, 3 months after surgery, and 6 months after surgery. RESULTS: Best corrected visual acuity (BCVA) improved in 100 of 122 eyes (82.0%). BCVA remained the same in 20 of 122 eyes (16.4%) and decreased in 2 of 122 eyes (1.6%), mainly because of coexisting age-related macular degeneration (AMD). The BCVA 3 months after surgery was ≥0.8 in 23 of 122 eyes (18.9%), between 0.5 and 0.7 in 28 of 122 eyes (22.3%), and between 0.2 and 0.4 in 33 of 122 eyes (27.1%). We found significant implications of cataract surgery on decreasing IOP in the studied group of patients suffering from glaucoma compared to the patients without glaucoma. CONCLUSION: Advanced age is not a contraindication for cataract surgery. The results of the study showed that when systemic conditions are stable, both phaco and ECCE with IOL for very elderly patients are effective and safe.

Aggregation and deformability of erythrocytes in primary open-angle glaucoma (POAG); the assessment of arterial hypertension.

Primary open-angle glaucoma (POAG) is one of the most common types of glaucoma. Glaucoma is a progressive neuropathy of the optic nerve with characteristic visual area disorders. The aim of this study was to assess the correlations between rheological parameters of blood and other parameters such as: intraocular pressure, visual acuity, angular breadth of the aqueous fluid eluvium, visual area and arterial hypertension. The examined group was comprised of 54 patients with POAG. Out of this group two subgroups was separated: I subgroup of 24 patients without hypertensive and II subgroup of 30 patients with chronic hypertensive disease. The control group was comprised of 40 healthy subjects. Erythrocyte aggregation and deformability analysis were determined using LORCA. From the results we concluded that rheological disorders such as enhanced erythrocyte aggregation or significantly decreased erythrocyte deformability occur in patients with POAG. Additionally, it revealed a significant relation between the duration of hypertension and an increased erythrocyte aggregation index (r = +0.27 p < 0.005) along with decreased deformability (r = -0.37 p < 0.001), where the decrease in deformability correlated with the severity of hypertonic retinal angiopathy (r = -0.30 p < 0.05). All these disorders may result in decreased blood flow to the optic nerve, which contributes towards the development of neuropathy.