Biomedical subjects

M C Blayo

Publications and source records attributed to M C Blayo.

At least 37 records · Page 2Linked to original sources

PubMed1976

Lack of effect of methemoglobinemia on the plasma-erythrocyte pH relationship.

A stable and reproducible methemoglobinemia is induced by small concentration of an oxidizing gas (NO). Under such conditions we evidenced that plasma pH (pHe) to erythrocyte pH (pHi) relationship is unchanged. A strong acidity bound to the changes of NO in water occurs. But we may conclude that the buffer capacity of erythrocyte is not modified by the oxydation of ferro into ferrihemoglobin within the erythrocyte.

Acid-Base Equilibrium↗

PubMed1975

Ccomparison of cisternal and lumbar cerebrospinal fluid pH in high altitude natives.

Samples of cisternal or lumbar cerebrospinal fluid were obtained from 20 young male volunteers born and living at high altitude (3500 to 4800 m). The pH, carbon dioxide and oxygen tensions, and bicarbonate concentration were measured and compared with those in the arterial and jugular venous blood. A consistent difference between the two CSF compartments was noted, particularly a lower pH (0.05), a higher PCO2 (7 Torr), and a lower PO2 (7 Torr) at the lumbar site. Mean bicarbonate concentration was not significantly different at the two sites. The main factor is PCO2, which controls the pH variation. These differences were more marked in high-altitude natives than in man at sea level. The existence of a consistent inhomogeneity of CSF acid-base content emphasizes the inaccuracy of using lumbar CSF pH to estimate the ECF pH as regulator of pulmonary ventilation and determinant of cerebral blood flow.

Acid-Base Equilibrium↗

PubMed1975

Assessment of Scholander micromethod for gas concentrations versus weighing method.

Three gaseous mixtures in N2, of varying concentrations of CO2 (3.60, 5.79, and 9.36%) and O2 (22.18, 15.12, and 6.82%), respectively, were prepared by precise weighings, which may serve as absolute measures. These mixtures were analyzed with two apparatuses by the Scholander micromethod. Taking into account the influence of several factors (apparatuses, order of analyses, etc, it appears that differences between apparatuses were not significant in five of six cases and the effect of order was significant in O2 (P less than 0.01) but not in CO2 for the set of measurements. When compared with weighings, measurements differed only in one apparatus (P less than 0.02) in two of six cases and by no more than 0.02%. The relation between weighings and measurements was highly significant (P less than 10(-9) and no lack of fit to linearity occurs. Side effects of the factors considered and interactions between them are discussed. In conclusion, the micromethod of Scholander gives accurate results, in very good agreement with the reference values provided that certain technical precautions are observed.

Carbon Dioxide↗

PubMed1974