Combined Enzymatic Reaction for Nervous and Muscular Tissues (Cholinesterase and succinic dehydrogenase)

A technique for revealing cholinesterase and succinic dehydrogenase activities in the same frozen section has been developed. This method permits economy of material and appreciation of alterations in both nervous and muscular tissues with one microscopic examination; it is of value to pathologists concerned with diseases of muscle, especially amyotrophies of nervous origin.     

Cell size as an indicator of changes in intracellular composition of Azotobacter vinelandii.

Cell size, measured electronically, was correlated to changes in cellular composition, number, and morphology of Azotobacter vinelandii OP during batch growth. The effect of a changing abiotic environment on these features of the cell is discussed. For this organism exponential growth was unbalanced growth and cell-size change was a sensitive indicator of this growth pattern. Cell-size measurements have the potential to give a rapid assessment of intracellular compositional changes.     

Identification of 3-deoxyglucosone dehydrogenase as aldehyde dehydrogenase 1A1 (retinaldehyde dehydrogenase 1)

One of the metabolic fates of 3-deoxyglucosone, a product of protein deglycation and a potent glycating agent, is to be oxidized to 2-keto-3-deoxygluconate, but the enzyme that catalyzes this reaction is presently unknown. Starting from human erythrocytes, which are known to convert 3-deoxyglucosone to 2-keto-3-deoxygluconate, we have purified to near homogeneity a NAD-dependent dehydrogenase that catalyzes this last reaction at neutral pH. Sequencing of a 55 kDa band co-eluting with the enzymatic activity in the last step indicated that it corresponded to aldehyde dehydrogenase 1A1 (ALDH1A1), an enzyme known to catalyze the oxidation of retinaldehyde to retinoic acid. Overexpression of human ALDH1A1 in HEK cells led to a more than 20-fold increase in 3-deoxyglucosone dehydrogenase activity. In mouse tissues 3-deoxyglucosone dehydrogenase activity was highest in liver, intermediate in lung and testis, and negligible or undetectable in other tissues, in agreement with the tissue distribution of ALDH1A1 mRNA. 3-deoxyglucosone dehydrogenase activity was undetectable in tissues from ALDH1A1(-/-) mice. ALDH1A1 appears therefore to be the major if not the only enzyme responsible for the oxidation of 3-deoxyglucosone to 2-keto-3-deoxygluconate. The urinary excretion of 2-keto-3-deoxygluconate amounted to 16.7 micromol/g creatinine in humans, indicating that 3-deoxyglucosone may be quantitatively a more important substrate than retinaldehyde for ALDH1A1.     

Maqua (therapeutic burn) as an indicator of underlying disease

The origin and nature of the maqua (the Arabic therapeutic burn) is presented together with our clinical experience of patients previously treated by this traditional method. Maquas are small deep burns inflicted in areas either in proximity to a diseased organ or in points related traditionally to the original basic problem. These relationships may be rooted in historical ties between old Arab medicine and traditional Oriental, antique Egyptian, and Greco-Roman medicines. Maquas alone only rarely present a threat to the patient, but in many cases they may serve as an indicator of the original underlying disease. This and other folklore treatment modalities, together with the healers themselves, should be acknowledged by us, as markers for health problems or maybe for potential healing methods and doctor-patient relationships.     

SNARF-1 as an intracellular pH indicator in laser microspectrofluorometry: a critical assessment

The use of SNARF-1-AM (seminaphtorhodafluor-1-acetoxymethylester) to measure the internal pH of a single living cell by laser microspectrofluorometry has been analyzed with a lymphocyte murine B cell line A20. After incubation of the cells at 37 degrees C in the presence of 10 microM SNARF-1-AM, the internal concentration of SNARF-1 was approximately 200 microM. The enhancement of fluorescent intensity of the probe is concomitant with its leakage out of the cells. During the measurement period, this induces a continuous increase of the contribution of the external probe to the total fluorescence intensity. This prevented classical spectrofluorometry measurements, but did not preclude microspectrofluorometry measurements of internal pH. The ratio R was calculated from fluorescence intensities at 635 and 590 nm and used as an indicator of the intracellular pH. Calibration curves of the intracellular pH were obtained in the presence of nigericin and valinomycin. It appeared that both the fluorescence intensity and the ratio R were lower inside the cell than those values obtained in aqueous solutions. Possible interactions with the main biological macromolecules (i.e., DNA, proteins, membranes) were investigated as well as a possible compartmentation of the probe in cellular organelles. The modifications of probe characteristics inside the cells were attributed to the binding of the probe to cellular proteins. The intracellular pH of A20 cells, measured by SNARF-1 on 84 cells, was found to be 7.18 +/- 0.10 (with an external pH of 7.40 +/- 0.05), which corresponded with values obtained by conventional fluorometric methods.