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Aqueous ragweed pollen extracts (20,000 PNU/ml or 78,000 PNU/ml) lose 50% of their Antigen E content within 5 months of storage at 4 degrees C. Glycerinated extracts and lyophilized ragweed pollen extracts retain their Antigen E content for over 15 months with little or no loss. The preservative phenol in aqueous extracts is destructive to Antigen E probably by protein denaturation. The stability of ragweed extracts as measured by Antigen E content is markedly enhanced with little loss after 15 month storage at 4 degrees C, when the extract is prepared as an alum precipitated suspension.

Rosoxacin, a new synthetic antimicrobial agent, has a wide spectrum of activity that may prove beneficial in the treatment of ocular infections. To determine the penetration of rosoxacin into ocular tissues and serum of the rabbit after topical, subconjunctival, and intravenous (IV) administration, rosoxacin levels were measured using a microbiological assay after enzymatic digestion of the ocular tissues. Quantities of rosoxacin that should prove to be of therapeutic value were detectable in the anterior segment of the eye after topical or subconjunctival administration. Subconjunctival administration also resulted in high levels in the retina and choroid area and in the optic nerve. Low levels were detected in the retina and choroid 15 minutes following IV injection; however, no detectable levels were found in the ocular tissues after this period.

This double-blind study provides evidence that skin testing with dialyzed Hymenoptera venoms is a more accurate, reliable method of diagnosing hypersensitivity to the sting of honeybee, yellow jacket, yellow hornet, white-faced hornet, and wasp than is skin testing with the corresponding whole body diagnostic allergenic extract. Furthermore, the incidence of false-positives was greatly reduced by using the dialyzed Hymenoptera venom (HDV) diagnosis. In this clinical trial, most sensitive individuals had skin test reactions greater than the diluent control at concentrations of 1 mug/ml or below. Levels of venom diagnostic of 100 mug/ml appeared to produce nonspecific local irritation. Skin test with whole body diagnostic allergenic extract did not produce a consistent differentiation between sensitive and nonsensitive individuals. No untoward reactions were seen using the dialyzed Hymenoptera venom (HDV) diagnostic.

To our knowledge, this is the first report of a topically applied, specific adenylate cyclase activator that reduces intraocular pressure. Forskolin, a novel adenylate cyclase activator, is reported to increase cyclic adenosine monophosphate (AMP) in intact cells. Cyclic AMP levels are increased with various antiglaucoma agents. Intraocular pressure in rabbits was significantly reduced with two concentrations of forskolin, 0.1% and 0.05%. Ocular hypertension was noted with 0.05% and 0.2%. No change in IOP was noted with 0.01% forskolin. The IOP lowering with 0.1% and 0.05% forskolin lasted approximately six hours. Mild, transient conjunctival chemosis was noted in the doses that decreased IOP. The contralateral control eye showed decreases in IOP, but the differences between control and tested eyes were significant by the Student's paired t test.

A simple, relatively fast, coulometric method to determine both the surface-moisture and bound-moisture content of a wide variety of lyophilized, allergenic extracts has been developed. The method has been found suitable for the detection of residual-moisture levels in both lyophilized protein and carbohydrate samples. Isothermal rate-changes in moisture desorption, normalized with respect to sample size and plotted versus time, yield desorption curves which are characteristic of several individual classes of lyophilized materials. The method, when compared to the Official Loss on Drying Procedure for Lyophilized Biologicals, has proven to be faster (1.5 hr.) and more sensitive, with increased specificity and accuracy.

Protoplast membranes from Streptococcus pyogenes incorporated rhamnose into a preexisting polysaccharide when incubated with thymidine diphosphate rhamnose-C(14). This polysaccharide, when extracted from the membranes, did not give a precipitin reaction with group A antisera, but could be coprecipitated with added group A polysaccharide by acetone. It is presumed to be a precursor to group specific polysaccharide of the streptococcal cell wall.

Zeleznick, L. D. (CIBA Pharmaceutical Co., Summit, N.J.), H. Hankin, J. J. Boltralik, H. Heymann, and S. S. Barkulis. Purification and properties of N-acetyl-d-glucosamine kinase from Streptococcus pyogenes. J. Bacteriol. 88:1288-1295. 1964.-A kinase from Streptococcus pyogenes which catalyzes adenosine triphosphate-dependent phosphorylation of d-glucose and N-acetyl-d-glucosamine has been purified 1,500-fold. The ratio of the enzymatic activity on both substrates remained constant throughout the fractionation. Similarity in heat stability, p-hydroxymercuribenzoate inhibition, protection by either carbohydrate, and lack of repression of enzymatic activity when the bacteria were grown exclusively on one of the two substrates supports the hypothesis that kinase activity is associated with one enzyme.

The use of mutants of Salmonella typhimurium in which biosynthesis of specific lipopolysaccharide precursors is blocked has made possible both biosynthetic studies and structural analyses which provide the basis for the structure of the core polysaccharide shown in Fig. 6. The simplest mutant, which is unable to synthesize UDP-glucose, forms only the backbone structure, containing heptose, phosphate, and keto-deoxyoctonate. To this backbone are attached side chains containing glucose, galactose, and N-acetylglucosamine. The resulting core structure is found in the lipopolysaccharide of the rough strain, as well as in that of the GDP-mannose- deficient mutant. In the wild type organism, long O-antigenic chains composed of repeating units containing galactose, mannose, rhamnose, and abequose are linked to the core, perhaps to the N-acetylglucosamine residue, as indicated in Fig. 6. The rough phenotype could presumably arise from mutation either at the level of nucleotide sugar synthesis or at some stage in assembly or attachment of the O-antigenic side chains. The pathways of nucleotide sugar synthesis appear to be normal in most rough strains of S. typhimurium (42), a finding which suggests loss of a lipopolysaccharide transferase reaction in these mutants. The site of the enzymatic defect has not yet been established in these cases, but two distinct genetic types of rough mutants have been detected (18). It is interesting to speculate about the function of the lipopolysaccharide. The lipopolysaccharide can account for as much as 5 percent of the dry weight of the cell, and its synthesis clearly involves major expenditure both of energy and of material. Yet loss of the antigenic side chains, or even of a major part of the core structure, appears to have little or no effect on the ability of the organism to survive under laboratory conditions, since the rough and mutant strains grow as well as the wild type does. However, only the wild types, possessing the complete antigenic side chains, are pathogenic. It is possible that the lipopolysaccharide is an important factor in aiding the bacterium to evade host defense mechanisms, such as phagocytosis. Such a role is well established for the capsular polysaccharides of the pneumococci. No mutants have thus far been detected which lack the backbone or lipid portions of the lipopolysaccharide. It may be that these parts of the lipopolysaccharide play an essential role in the physiology of the organism

A pH indicator and dextrose were incorporated into growth media as a modification of microbial microtiter methods for determining the minimal inhibitory concentration of antimicrobial drugs. This modified method was tested to evaluate the ease of reading end points by changes in the indicator color. Application of the procedure to two media, three indicators, and eight species of bacteria indicated that definitive end points could be reached as a result of indicator color change caused by acid production during bacterial growth. This method is accurate and reproducible. It is a modification which eliminates a need for plating and facilitates the reading of minimal inhibitory concentration end points.