SMAS-platysma face lift

Correction of laxity in the submental area and of hypertrophic neck cords has been enhanced with the SMAS-platysma face life over that which was achieved with a standard skin face lift. Evaluation of a 6-year experience with the SMAS-platysma face lift reveals that the operation can be safely performed with an acceptably low incidence of complications. The incidence of hematoma and associated complications is less than that which occurs when cervical and submental defatting is performed in conjunction with a skin face lift.     

Current chemical concepts of acids and bases and their application to anionic ("acid") and cationic ("basic") dyes

In biomedical studies, dyes are divided into "acid" and "basic" dyes. This classification cannot be reconciled with current chemical definitions of acids and bases. Br?nsted-Lowry acids are compounds that can donate protons; bases are proton acceptors. The definition of acids and bases is independent of the electric charge, i.e. acids and bases can be neutral, anionic or cationic. Reactions between acids and bases result in formation of new acid-base pairs. Lewis acids and bases do not depend on a particular element, but are characterized by their electronic configurations. Lewis bases are electron donors; Lewis acids are electron acceptors. This classification is also unrelated to the electric charge. Lewis acids and bases interact by formation of coordinate covalent bonds. In histochemistry and histology, dyes containing -SO3-, -COO- and/or -O- groups are classified as "acid" dyes. However, such compounds are electron pair donors and hence Br?nsted-Lowry and Lewis anionic bases. Dyes carrying a positive charge are termed "basic" dyes. Chemically, many cationic dyes are Lewis acids because they can add a base, e.g. OH-, acetate, halides. The hypothesis that transformation of -NH2 into ammonium groups imparts "basic" properties to dyes is untenable; ammonium groups are proton donors and hence acids. Furthermore, conversion of an amino into an ammonium group blocks a lone electron pair and the color of the dye changes drastically, e.g. from violet to green and yellow. It appears therefore highly unlikely that ammonium groups are responsible for binding of cationic ("basic") dyes. In histochemistry, it is usually not of critical importance whether anionic or cationic dyes are chemically acids or bases.(ABSTRACT TRUNCATED AT 250 WORDS)     

beta-Glucosidase activator protein from bovine spleen ("coglucosidase")

β-Glucosidase-stimulating proteins (“co-β-glucosidase”) have been isolated from bovine spleen by acidification of homogenized spleen, heat denaturation, and chromatography with DEAE-Sephacel, Sephadex G-75, hydroxyapatite, and decyl agarose columns. Gel electrophoresis of the product revealed a trace of inert protein and two fast-moving bands, a major diffuse band and a minor, faster-moving band. The latter two bands could be eluted from the gel and shown to stimulate a glucosidase preparation from bovine spleen. They both stained with Stains All and fast green, but poorly with Coomassie blue. The bands could also be visualized by ultraviolet scanning. Periodate-Schiff stain was positive for the major band. The M_r of the coglucosidase was about 20,400 as measured with the gel permeation column, but 4900 as measured with a Sephacryl S-200 column containing guanidine hydrochloride and roughly 6200 as measured by gel electrophoresis with Na dodecyl sulfate. A pI of 4.3–4.4 was indicated by isoelectric focusing. Neutral sugar was found to be present, but no sialic acid. It was destroyed by Pronase, but not by lyophilization, N-ethylmaleimide, or alkaline phosphatase. Stimulation of the basal activity (1 nmol/h assayed with methylumbelliferyl glucoside) was 50% when 0.15 μg/ml of coglucosidase was included in the incubation. The activating protein raised the V values and lowered the K_m values when both glucosyl ceramide and the artificial substrate were used. In contrast, phosphatidyl serine raised both the V, and the K_m for cerebroside hydrolysis. The activator protein was found to occur in the soluble part of spleen as well as in the mitochondrial and lysosomal fractions.