Role of the neuroglia of human ocular transparent structures in the visual perception concepts.

Physically transparent cornea, lens, and vitreous body are not transparent from histophysiological viewpoint and hence, cannot directly transmit light to the retina. The lens forms from two primordia in the course of the eye development: ectodermal (for capsular epithelium) and neuroglia (for lenticular stroma). These data suggest that the neuroglia migrating from the internal leaflet of the ocular goblet is a source of stromal fibroblasts of the corneal proper substance and also presents the fibroblast differons in the human ocular vitreous body and in the lenticular posterior pole. The common source in the development of the stroma of the transparent structures of the eye is explained and confirmed by the fact that the cornea, lens, vitreous body, and the retinal and brain neuroglia contain special proteins common for all these structures, crystallins. The structural relationship and origin of fibroblasts of the transparent ocular media underlie the identical functions of crystallin production; the physical and chemical characteristics of crystallins prevent the diffusion of light and cumulate it in one direction. In addition, our data on the neuroglial origin of the lenticular stroma suggest that the lenticular cells can act as Muller's glia, regulating the transformed energy flow. Hence, the fibers and stromal cells of the cornea, lens, vitreous body, and retinal glia can serve as components of the universal conduction system perceiving light, transforming it into another type of energy (presumably into electromagnetic waves or some motor pulse), and only then sending it to the photosensor cells. As a result, we have one-way light conduction due to stromal cells of transparent eye structures and inability of the retina to identify these cells. We therefore conclude that the cells located in front of the retina are invisible for the photoreceptors, because they conduct stimulation being not transparent in the physical sense, but just physiologically. We see only what this unique conduction system allows us to see.

[Diagnosis of left-ventricular diastolic dysfunction in patients with predialysis chronic renal failure]. / Diagnostika diastolicheskoi disfunktsii levogo zheludochka u bol'nykh s dodializnoi khronicheskoi pochechnoi nedostatochnost'iu.

AIM: To specify effectiveness of different methods for assessment of diastolic function in patients with pre-dialysis chronic renal failure (CRF). MATERIAL AND METHODS: Forty non-diabetic pre-dialysis CRF patients (20 males and 20 females, mean age 51 +/- 11 years) were studied. Serum creatinine was 209.3 +/- 117.4 mcmol/l. 19 patients had chronic heart failure (CHF) of NYHA class I-III. M-mode echocardiography and Doppler echocardiography were performed. Transmitral and pulmonary venous flows were assessed by Doppler echocardiography and the flow propagation velocity (Vp) was estimated by color M-mode Doppler echocardiography. The ratio of peak E-wave velocity of transmitral flow to Vp (E/Vp) was calculated. All the patients had preserved systolic function (ejection fraction > 45%). RESULTS: Interpretation of transmitral flow was difficult in 16 (40.0%) patients. During Valsalva's manoeuvre the E-wave peak velocities, the A-wave velocities and the ratio E/A were decreasing. However, we did not reveal any correlation between E/A and NYHA class of heart failure (r = 0.18; p = 0.32). Interpretation of pulmonary venous flow was possible only in 24 (60.0%) patients. Vp estimation by color M-mode Doppler echocardiography improved evaluation of diastolic function in 15 of 16 patients with problems of transmitral flow assessment. A negative correlation was revealed between NYHA class and Vp (r = -0.39; p = 0.013) and a positive correlation was between NYHA class and E/Vp (r = 0.45; p = 0.004). CONCLUSION: Vp assessed by color M-mode Doppler echocardiography improves the diagnosis of diastolic dysfunction in patients with chronic renal insufficiency. This method has an advantage over pulmonary venous flow investigation. The Valsalva's manoeuvre is low-effective for differential diagnosis of transmitral flow types.

[Impact of day-to-day arterial pressure variability on the left ventricle geometry in patients with predialysis chronic kidney insufficiency]. / Vliianie mezhsutochnoi variabel'nosti arterial'nogo davleniia na geometriiu levogo zheludochka u bol'nykh s dodializnoi khronicheskoi pochechnoi nedostatochnost'iu.

AIM: To estimate the impact of day-to-day variability of blood pressure (BP) on left ventricular geometry in pre-dialysis patients. MATERIAL AND METHODS: We estimate the impact of day-to-day variability of BP on left ventricular geometry in 42 non-diabetic pre-dialysis patients (22 F, 20 M, mean age 47 +/- 12 years) with arterial hypertension (> 140 and 90 mm Hg). Serum creatinine was 286.2 +/- 176.8 micromol/l. BP was measured in the morning during 12 days and M +/- SD and delta systolic blood pressure (dSBP = SBPmax - SBPmin) was calculated. Echocardiography was performed and left ventricular mass index and relative wall thickness (RWT) was estimated. RESULTS: LVH was detected in 35(83.3%) patients. Multiple stepwise regression analysis revealed that mean SBP is a stronger predictor of LVH than clinical SBP (R2 = 0.59; p = 0.000001 and R2 = 0.35; p = 0.0007, resp.). Standard deviation of mean SBP correlated with RWT (R2 = 0.30; p = 0.006). dSBP > 30 mmHg was associated with an increase of RWT. CONCLUSION: Mean SBP during 12 days is a stronger predictor of LVH than clinical SBP. Day-to-day variability of SBP with dSBP > 30 mm Hg was associated with development of concentric LVH.

[Heart remodeling in patients with predialysis phase of chronic renal failure]. / Remodelirovanie serdtsa u bol'nykh s khronicheskoi pochechnoi nedostatochnost'iu v stadii, ne trebuiushchei dializa.

AIM: To investigate remodeling of the heart in patients with predialysis phase of chronic renal failure (CRF). MATERIAL AND METHODS: Patients with predialysis phase of CRF (n = 61; serum creatinine 412.4 +/- 242.69 mumol/l), essential hypertension (EH) (n = 35) and healthy volunteers (n = 20) were assessed with echocardiography. The patients were not significantly different by the level of systolic and diastolic blood pressure, age and gender. RESULTS: Left ventricular mass index (LVMI) was increased in 53(86.9%) patients with CRF. LVMI was not different in patients with CRF and EH (189.9 +/- 71.35 vs. 165.0 +/- 41.83 g/m2; p = 0.3). Relative wall thickness was similar in patients with serum creatinine < 200 mumol/l and patients with more elevated serum creatinine (57.2 +/- 10.33 vs 58.31 +/- 13.33; p = 0.9). The ejection fraction lower than 50% was detected in 14(22.9%) patients with CRF. Multivariate regression analysis showed that LVMI was independently related to systolic blood pressure (p = 0.004) and level of hemoglobin (p = 0.004). Diastolic dysfunction (early and atrial peak filling velocities ratio < 1.0) was detected in 13(50%) from 26 investigated patients with CRF. The independent influence of hemoglobin on isovolumic relaxation time (p = 0.04) and early and atrial peak filling velocities ratio (p = 0.02) are shown. CONCLUSION: In patients with predialysis phase of CRF left ventricular hypertrophy (LVH) is extremely common including patients with mildly elevated serum creatinine. The treatment of patients with renal pathology and normal function must include measures not only to correct renal process but also to prevent development of LVH.

[Effects of arterial compliance on geometry of the left ventricle in patients with pre-dialysis chronic renal failure]. / Vliianie arterial'noi podatlivosti na geometriiu levogo zheludochka u bol'nykh s dodializnoi khronicheskoi pochechnoi nedostatochnost'iu.

AIM: To examine relationships between left ventricular geometry and general arterial compliance (GAC) in patients with predialysis chronic renal failure (CRF). 102 patients with predialysis CRF unrelated to diabetes mellitus (males 46, females 56, mean age 49.1 +/- 18.3 years). CRF was caused by chronic glomerulonephritis and essential hypertension (77.4%). 92 (90.2%) patients were hypertensive. Serum creatinin was 432.1 +/- 165.3 mcmol/l. GAC was defined as stroke volume/pulse arterial pressure. Echocardiography determined the index of the left ventricular myocardial mass (ILVMM), relative thickness of the left ventricular wall (RTW). Left ventricular hypertrophy (LVH) was diagnosed in 86 (84.3%) patients. In 64 patients it was concentric and in 22 patients--excentric). Multivariance regression analysis showed that systolic arterial pressure and anemia have a direct independent effect on ILVMM (p = 0.004). Independent inverse relationship was between GAC and RTW. Patients with concentric LVH had GAC lower than those with excentric LVH (p = 0.003). Reduction of GAC is an independent factor influencing the development of concentric LVH in patients with predialysis CRF.