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Biomedical subjects

P G Data

Publications and source records attributed to P G Data.

At least 37 records · Page 2Linked to original sources

[Computerized system for the acquisition and analysis of bioelectric waves].

With collaboration of medicals, electronics and informatics; we have evaluated a method destined to be a potent instrument for the analysis and store of bioelectrical signal. The signal can be taken directly from the subjects or from a tape recorder; we can call again stored for evaluating the gradient grade, the integral and other mathematical evaluations of traits of a curves; in example EEG, EOG, PEV, etc.

Computers↗

[Respiratory and cardiac activity during sleep at high altitude (4650 m. above sea level)].

In this study, the relationship between the cardiac rhythm and ventilatory rhythm, during the sleep, at high altitude (4560 s.l.- Peruvian Andes) has been evaluated in native acclimated, and long-term resident people. The experimental observation has been performed from 11.00 p.m. to 7.00 a m. (when the barometric pressure was 430 mmHg, pO2 was 90 mmHg and paO2 was 71 mmHg) by using an eight channel polygraph for EEG, usefully modified for ECG and pneumographic recordings. In agreement with the observations of other Authors, a periodic breathing was recorded when the theta rhythm (low amplitude waves, characteristic of the second stage of the sleep) appeared in the EEG. During the REM stage of the sleep, the respiration becomes irregular, without periodicity in the ventilatory rhythm. Any statistical difference was not observed between European and Andinian subjects. During the N-REM phases of the sleep, the cardiac activity was often clearly dissociated from respiratory cycles. This finding suggests that, during the 2 and 4 phases of the sleep, in our experimental conditions, the cardio-inhibitory and cardio-acceleratory centers seem to lose the correlation with the regulatory centers of the breathing.

Adult↗

Cardiac output and gas exchange during heavy exercise with a positive pressure respiratory protective apparatus.

Cardiac output and gas exchange during heavy exercise with a positive pressure respiratory protective apparatus. Scand j work environ health 9 (1983) 471-477. Continuous positive pressure breathing effectively prevents inward leakage of noxious agents into a breathing apparatus but may interfere with venous return and cardiorespiratory performance during heavy work. Cardiac output was therefore recorded with a dye dilution method, and ventilatory variables were measured from expired air, for seven well-trained firemen at a work load of 150 W. All the variables except the invasive ones were also measured during the maximal work load that each subject could sustain for 10 min. At random the subjects worked with a mouthpiece and a face mask with and without a positive pressure of 0.4 kPa. No variable deteriorated during positive pressure breathing, although the central venous oxygen pressure increased, an occurrence indicating higher cardiac output in relation to oxygen demand. Dead space ventilation decreased, an indication of increased ventilatory efficiency. Positive pressure breathing (0.4 kPa) thus does not deteriorate cardiopulmonary function during intermediate or maximal work loads.

Adult↗

[Evaluations of respiratory functional parameters in sponge fishers from the island of Kalimnos (Greece)].

We had intended to study functional respiratory patterns of a sponge-divers group from the Island of Kalymnos (Greece). Such a group constitutes a very homogeneous sample for dietary habits and underwater activity, handed down from father to son. Some of these sponge-divers dives holding his breath; others use "narghilè", a special apparatus consisting in a nosepiece connected to an air compressor placed in the boat. As their activity is continuative and prolonged for several months in the years with repeated dives from dawn to dusk, and because air output of narghilè is nearly constant, it is possible to deduce that in these subjects functional respiratory modifications are occurred. After evaluated three groups (skindivers, narghilè-divers and control-group) we didn't notice any particular change of static and dynamic pulmonary volumes. Only Expiratory Reserve Volume is higher in spite to Knudson's values; this is probably due to psychological and emotional factors.

Diving↗

[Findings of the importance of dietetic fiber in the regulation of cholesterolemia].

We studied the variations of some lipid indexes in cholesterolemia, lipidemia and triglycerides in relation to a diet rich in bulk. Seven adult male subjects in good health were tested for cholesterol, lipid and triglycerides before and after a two week period of a dialy diet of 40 g of whole wheat bran containing about 10g of fiber. At the some time the lipid, cholesterol and triglycerides limits were measured in 3 groups of rabbits. The first groups was subjected to a normal diet, the second group was subjected to a diet of bleached flour and vitamins, and the third group had a diet similar to the second group but with the addition of 40 g whole wheat bran. The results of our investigation demonstrated a statistically significant decrease of cholesterol lipid and triglycerides levels the special diets at the some time we did not see in increase in the third group of rabbit. Our study seems to indicate that dietetic fibers exercise a vital role in regulating the concentration of plasma lipids even if the subject continues to consume a diet rich in fats. From this we see to importance of the dietetic fibers as a protective factor in the prevention of ateriosclerotic.

Adult↗

[Evaluation of various hematologic parameters in Andean miners (Morococha-Peru 4560 m)].

In other Author's previous studies refer that prolonged CO exposure, as chronic altitude exposure, causes marked increases in Hb and Htc levels. We had intended to study these hematologic changes on three non-smokers' group : Miners of the Andes working at CO exposure ambients, Residents and European Subjects living a. s. l. and exposed at 4560 m. Statistical analysis, according with literature, has shown significant difference in the three groups' Hb and Htc ratio, in comparison with sea level control values. We had moreover observed that HbCO of the Miners' group reached, sometimes, 8, 2% values. It does not seem, however, that the higher HbCO levels noted in the Miners' group are sufficiently elevated for producing a further increase in Hb and Htc ratio compared to the other two control group.

Adult↗

[Blood sugar and the hematocrit: relation to acclimatization at 4560 m. altitude].

We had intended to study the relation between glycemia and hematocrit during high altitude acclimatization (Morococha, Peru-4560 m) and to observe if, subsequently to an increase of hematocrit, glycemia should become lower. From obtained results upon 176 hematologic observations of glycemia, hematocrit, hemoglobin and erythrocyte production, on 38 healthy European subjects (27-58 years aged), it doesn't result, from the first analysis, the existence of this relation. We reserve ourselves, in any case, to accomplish further tests, such as insulinemic dosage for evaluating pancreatic activity.

Adult↗

[Hemodynamic modifications induced by volatile anesthetics halothane, penthrane, ethrane) I. Cardiovascular effects].

UNLABELLED: We had intended to reckon quantitatively the effects of volatile anaesthetics(Halothane, Ethrane, methoxyflurane or Penthrane) upon cardiovascular system of healthy young mongrel dogs, 5-8 days interval each other. After administration of a Halothane and Penthrane, heart rate(HR) increases of about 30%; blood pressure(BP) is decreasing of same percentage. Halothane causes a slight increase upon pulmonary arterial pressure(PAP), while pulmonary arterial flow(PAF) reaches 40% more than control values. Penthrane decreases of 30% PAP and of about 40% PAF. Ethranic anaesthesia produces a slight fall on HR and BP, while PAP doesn't result significatively modified; a marked decrease(40%) is observed on PAF. Aortic flow(AF) is diminished(from 20 to 30%) by administration of these anaesthetics. IN CONCLUSION: Halothane causes very significative modifications on circulation, less modifications are produced by Penthrane, while Ethrane doesn't produce any changes.

Anesthetics↗

[Hemodynamic modifications induced by volatile anesthetics halothane, penthrane, ethrane). II. Effect on myocardial contraction and myocardial response to hypoxia].

We had intended to reckon quantitatively the effects of volatile anaesthetics about myocardial contractility and coronary circulation, on rest and after total occlusion of the left circumflex coronary artery for 15 sec on young healthy mongrel dogs. Halothane decreases coronary flow of about 20% while Penthrane increase coronary flow (CF) of 30% after 20 sec and later it stabilizes to 10% higher than the control values. Ethrane causes a light initial decrease and later CF returns to control values. During occlusion, derivative of left ventricular pressure (LVP) is reduced from Halothane, which also causes a marked decrement of hyperemia. By means of penthranic anaesthesia, during occlusive phase, we observed a shortening in contraction and relaxation speed. Ethrane doesn't modify the hyperemic coronary flow nor cardiodynamic parameters during occlusive period, while the latter parameters are sensibly varying during restore.

Anesthetics↗

[Blood coagulation in immersion in high altitudes].

At sea level, a group of four volunteers performed 20 m dives, three more hyperventilated on 12% O2 in N2 for 12 min and held their breaths for the longest time possible. All subjects were civilian sport divers. Hematocrit, hemoglobin, 2,3-DPG, plasma fibrinogen, prothrombin, alfa 1-antitrypsin, antithrombin III, plasminogen and whole-Blood Coagulation Time (BCT) were measured. 2,3-DPG was increased during high altitude permanence. Post-dive BCT was lenghtened (39%) at high altitude and shortened (30%) at sea level. No difference in BCT was detected after hypoxia hyperventilation. The results suggest that in chronic hypoxia biochemical and functional modifications take place in the blood affecting the length of BCT.

Adult↗

Effects of papaveroline-monosulphate on the systemic and regional circulation in the dog.

The effects of papaveroline 6'-sulphonic of N-methylglucamine (UTEN), administered by intravenous injection in doses ranging from 10 to 20 mg/kg, on cardiac dynamics and peripheral blood flow distribution were studied in conscious and anesthetized dogs, using electromagnetic flowmeters implanted around the ascending aorta, pulmonary artery, left coronary artery, superior mesenteric artery, and renal and external iliac arteries. In the conscious dogs, blood pressure after the injection of the drug showed an initial fall and returned to normal control values after a transitory increase. The changes in aortic pressure were accompanied by an increase in heart rate, cardiac output, stroke volume and cardiac work. The administration of UTEN was also associated with an increase in the peripheral blood flow and a decrease in their calculated resistances and in total peripheral resistances. Similar variations were observed in the anesthetized dogs. The effects of UTEN were compared with those of other vasodilator drugs (papaverine, isoxsuprine and D.E.D.). From the results obtained it is possible to conclude that UTEN produces a vasodilation in all investigated vessels, whereas other vasodilator agents only act in some particular vascular beds; moreover, the effect of UTEN is longer-lasting. There is also a probable constriction in the capacitance vessels, as shown by haemodynamic changes in the pulmonary circulation.

Animals↗

Thoracic and pulmonary radiographic modification during immersion in apnea: 1--a special apparatus.

Thoracic and pulmonary radiographic modification during immersion in apnea, were studied. An Apparatus "Nuclearisub" was used, it consists of two parts: An x-ray generator (100 KV, 40 mA) and a image intensifier tube (brightness gain 1200) with a transistorized telecamera. Through continuous radioscopy during immersion, can be analyzed the variations caused by redistribution of the blood, as well as the changes in pressure.

Apnea↗