Potassium level changes--arrhythmia contributing factor in chronic kidney disease patients.

UNLABELLED: As the renal function progressive decline is often correlated to diuresis impairment, potassium level changes represent a major pathophysiological factor in monitoring chronic kidney disease. Even more, potassium level imbalance could lead to life-threatening situations with the risk of severe rhythm disorders appearance. The aim of the study was to determine in which degree the serum potassium changes are implicated in arrhythmias development in CKD patients. PATIENTS AND METHODS: We included 678 CKD patients (predialysis and dialysed patients) to whom we recorded biohumoral and clinical features in correlations with the possibility of arrhythmias genesis. RESULTS: we noticed, in our predialysis group, an important correlation between hyper-/hypokalemia and arrhythmias appearance, more frequent during hypokalemia episodes (OR=4.04, respectively OR=7.5). The same situation was observed in chronic dialysis group. CONCLUSIONS: Hypokalemia is a stronger risk factor than hyperkalemia, but all together, any minimal changes in serum potassium levels could determine arrhythmia in CKD patients.

From visual consciousness to spectral absorption in the human retina.

In this paper, we present work that started as an interest in visual consciousness with the study of the blindsight phenomena and color processing. This led us to develop an intraocular reflection and absorption model of the human eye that is sufficient to account for luminance and color detection in blindsight subjects. Luminance and color thresholds were obtained in the good and blind field of hemidecorticated patients under controlled conditions. To determine the role of internal scatter and absorption properties of the human eye we tested the model predictions in three ways. By psychophysical means, by measuring absorption and scatter properties of the human eye, and by building an electromechanical sensor apparatus mimicking Lambertian reflection in the eye. The results of the simulations and measurements support the notion that the sensitivity functions obtained with the hemidecorticated patients can be explained by reflection and absorption properties of the human eye that have not been fully accounted for in the blindsight literature. In the light of such findings, future blindsight experiments must necessarily account for intraocular absorption and reflective properties of the human eye of the type described.

Residual vision in the blind field of hemidecorticated humans predicted by a diffusion scatter model and selective spectral absorption of the human eye.

The notion of blindsight was recently challenged by evidence that patients with occipital damage and contralateral field defects show residual islands of vision which may be associated with spared neural tissue. However, this possibility could not explain why patients who underwent the resection or disconnection of an entire cerebral hemisphere exhibit some forms of blindsight. We present here a model for the detection of intraocular scatter, which can account for human sensitivity values obtained in the blind field of hemidecorticated patients. The model demonstrates that, under controlled experimental conditions i.e. where the extraocular scatter is eliminated, Lambertian intraocular scatter alone can account for the visual sensitivities reported in these patients. The model also shows that it is possible to obtain a sensitivity in the blind field almost equivalent to that in the good field using the appropriate parameters. Finally, we show with in-vivo spectroreflectometry measurements made in the eyes of our hemidecorticated patients, that the relative drop in middle wavelength sensitivity generally obtained in the blind field of these patients can be explained by selective intraocular spectral absorption.

No blindsight following hemidecortication in human subjects?

Using a guessing paradigm we measured visual sensitivity in the blind and normal half-fields of four cerebrally hemidecorticated patients. In the blind field, sensitivity was reduced by approximately 3 long units. Stimuli which produced significant detection also evoked conscious sensations of light and colour. Control experiments showed that although sensitivity in the blind field depended in a normal fashion on background luminance it was independent of the luminance of a local platform, and showed no spatial summation. This residual vision can be explained by intraocular light diffusion and reflection.

Survey on some aspects of immunologic reactivity in old age.

The raport focuses on investigation of a sample of old people, mainly in their eighties, as against a control group of healthy subjects, aged between 25 and 40. In order to investigate the immunologic response the research has been carried on along the following lines. to show self Ab antinuclear (AAN), antimitochondrial (AM) and antismoth muscle (ASM), by using indirect immunofluorescence; to study alteration of serum immunoglobulins by using IDR; to study alteration of serum concentration of C3 fraction in the complement by using IDR; to determine immune complexes by using Haskova method; to investigate IR through R rosetting method. Immunologic reactivity (IR) disturbance was found, with respect to alteration of immunoglobulin ratio IgA, IgG, IgM vere slightly diminished. Self antibodies were present to a percentage of 17% as predominant of ASM, AM and AAN in decreasing order. Increase in C3 associated with increase in immune complexes could account for high incidence of cardio-vascular complications. Decline in IR is shown through the decrease in T lymphocytes where Ts is more markedly decreased as against decreased Ts. The results imbalance between stimulating activated cells and suppressive controlling cells. IR alteration could account for degenerative pathology in the subjects, namely, ATS, cardiovascular diseases, senility, pseudobulb syndrome, schizoaffective psychosis.

Immunologic alterations in the third trimester of pregnancy.

In a study carried out in a group of 61 pregnant women in the 21st to the 41st week of gestation and comparatively in 9 nonpregnant controls, the following were determined: changes in the leukocyte and lymphocyte count, proportion of T cell rosettes, T1 rosettes (TM cells), T2 rosettes (TG cells), EAC rosettes (B cells), EACD rosettes (killer cells), circulating NBT-positive phagocytes, serum IgG, IgA, IgM and C3 concentrations, 50% hemolytic activity of the complement system. The results are interpreted in the light of present data regarding the mechanisms of ovo-embryo-fetal allograft.

Metabolic investigations in persistent depressive states in the elderly.

In a group of 100 elderly patients with persistent depressive states, a series of investigations were carried out: hematologic, lipid, protein, energy metabolism hydroelectrolytic and acid-base balance, blood rheologic properties, immunologic, reactivity and certain humoral and regulation mechanisms. The results were compared with those obtained in two control groups, identical in number, the former in the third age without depressive states and the latter of healthy adults. The results were evaluated statistically. The results demonstrate that in depressive elderly subjects changes of the various parameters studied occur in the same direction as those in the group of elderly subjects without depression, but are far more accentuated.