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Biomedical subjects

S Cifaldi

Publications and source records attributed to S Cifaldi.

At least 19 recordsLinked to original sources

Finger tremor and the central nervous system.

It is well known that normal physiological tremor of the fingers and alpha rhythm in the EEG, may share a common frequency band in the region of 10 Hz; that these two characteristics may be in some way related as a function of their frequencies, is a hypothesis which needs to be tested, as one element in establishing the physiology of physiological tremor. Bilateral occipital EEGs and simultaneous measurements of acceleration from the terminal phalanx of the middle finger of both hands were recorded from eight subjects. The data were analysed to produce power spectral densities and coherence functions, the latter being used to reveal the presence or absence of frequency elements common to both signals. No evidence was found that would support a hypothesis that the two characteristics were in any way frequency related, from which it can be inferred that the tremor is not under central control. In addition, tremor of the right and left hands does not show a synchronous relationship.

Brain↗

The serum lipoprotein pattern of water buffalo (Bubalus bubalis).

1. The serum lipoprotein pattern of water buffalo was studied by means of electrophoresis and the lipoproteins were isolated by ultracentrifugation on the basis of their hydrated density. 2. High density lipoproteins (HDL) showed a higher level of cholesterol than did the other lipoproteins. Moreover, the level of phospholipids was higher in HDL than in very low density lipoproteins (VLDL). 3. The buffalo B100 apoprotein was similar to that of man and rat. Three apoproteins similar to human apo E, apo AI and AII were found in buffalo HDL, buffalo VLDL contained essentially apo B protein.

Animals↗

Digital sampling rate and ECG analysis.

The influence of sampling rate on the accuracy of measurements of various ECG parameters has been studied. Statistical analysis showed no significant difference between results obtained at sampling rates of 500 and 250 samples s-1. Recordings made at 125 samples s-1, however, showed significant reductions in peak amplitude values. Some interval measurements also varied significantly to both larger and smaller values. Other intervals did not seem to be affected significantly. It is concluded that a sampling rate of 125 samples s-1 could be used in particular conditions when only the measurement of certain intervals is required.

Biomedical Engineering↗

[Erythrocyte deformability determined by filtration].

Authors studied red blood cell filtrability by means of an original apparatus. The red blood cells were suspended in 0,9% NaCl and Teitel solutions. Teitel solution was the most usefullness in filtrability studies.

Erythrocytes↗

[Erythrocyte deformability dependent on variations in pH].

Authors studied the influence of pH changes on red blood cell deformability by means of filtration technique. In 0,9% NaCl solutions, there was decrease of RBC deformability upon both lowering and increasing of pH. In Teitel solutions, RBC deformability increased on alcalyne pH.

Erythrocytes↗

[Rheographic evaluation of peripheral blood flow during isometric exercise].

A rheographic evaluation of peripheral blood flow during isometric contraction (handgrip) has been done in 25 attendants of the Air Force Medical Service (mean age :20 years). The velocity of sphygmic wave, the sphygmic amplitude and, the peak time, heart rate and blood pressure have been measured at rest and during handgrip. The velocity of sphygmic wave does not change in all the subjects; the sphygmic amplitude is decreased of 10% (p less than .001), the peak time is decreased of 9% (p less than .001). Because sphygmic amplitude and peak time are directly proportional to flow volume, and their reduction significantly express a decrease of flow volume. The authors believe that the blood flow reduction is induced by the excitation of sympathetic peripheral alpha-receptors, not more balanced from sympathetic cholinergic vasodilator fibers. The actual result is an increase of the peripheral vascular resistances.

Adult↗

[Estrogen receptors in rabbit thymus].

The estrogen receptors presence or absence in the thymus gland represents the basic element to assert or to exclude any estrogenic action in the thymus. Now we have measured the presence of cytoplasmatic estrogen receptors in the female rabbits thymus, using some methods (sucrose gradient, protamine sulphate, dextran-coated charcoal). Finally, we have investigated, using the sucrose gradient assay, the nuclear ER presence in 1000g thymic pellet. The results exclude high levels of estrogen-binding proteins while don't suggest their total absence in the female rabbit thymus.

Animals↗