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)     

Pleomorphic ("dedifferentiated") chondrosarcoma. Report of a case initially examined by fine needle aspiration biopsy

Fine needle aspiration (FNA) biopsy of a predominantly radiolucent, destructive lesion of the right distal femoral metaphysis of a 69-year-old man produced smears containing spindle-shaped cells with cytologic features consistent with a malignant fibrous histiocytoma. This initial diagnosis was supported by immunoperoxidase staining, which was strongly positive for vimentin and alpha-1-antichymotrypsin, focally positive for S-100 protein and negative for desmin, muscle-specific actin, keratin, carcinoembryonic antigen and epithelial membrane antigen. Subsequent surgical resection revealed a lesion with a predominance of malignant fibrous histiocytoma-type regions; however, focal microscopic areas contained a low-to-medium-grade cartilaginous component. The final diagnosis rendered was thus pleomorphic or so-called "dedifferentiated" chondrosarcoma. This rare lesion should be included in the differential diagnosis of malignant spindle-cell lesions of bone assessed by FNA biopsy.     

Growth of microorganisms on chemically synthesized carbohydrate ("formose") syrups

Formose syrup was studied as a carbon source for growth of a series of microorganisms obtained from various collections. Approximately 80 strains of bacteria, yeasts, and molds were inoculated into a medium containing formose syrup and mineral salts supplemented with small amounts of yeast extract and casein hydrolysate to supply accessory growth factors. Two preparations of formose syrup, produced by two different laboratories, were employed. Formose syrup I, characterized by a low sugar content, was poorly utilized; syrup II, containing a higher sugar concentration, was utilized to a greater extent. Two strains of Aerobacter acrogenes yielded 1.3 g dry cell mass from an initial charge of 10 g of formose II solids, whereas growth on 10 g of D -glucose amounted to 3.7 g. Klebsiella aerogenes MIT-B44, the best microbial strain isolated from soil by an enrichment technique, produced 1.3 g cells from 10 g fromose syrup II solids in supplemented medium; in direct comparisons, it produced 10–15% more cell 0.7–0.9 g cells per 10 g formose and grew with a doubling time of 55–70 min. Under such conditions, its macromolecular composition was 52% protein, 22% RNA, and 2% DNA. Although the apparent yield of cells from formose was only 8–11%, the actual yield based on formose utilized was 30%, the same as observed with glucose. A second strain was isolated from soil by enrichment with spent broth from K. aerogenes. This unidentified gram-negative, short rod-shaped bacterium grew in mixed culture with strain MIT-B44; in unsupplemented media they produced 1.55 g cells from 10 g formose II solids and 2.9 g cells from 10 g glucose.     

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.