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Biomedical subjects

L D Zeleznick

Publications and source records attributed to L D Zeleznick.

16 recordsLinked to original sources

Forskolin, a potent adenylate cyclase activator, lowers rabbit intraocular pressure.

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.

Adenylyl Cyclases↗

Intraocular penetration of rosoxacin in rabbits.

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.

4-Quinolones↗

Diagnosis of Hymenoptera hypersensitivity by skin testing with Hymenoptera venoms.

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.

Animals↗

Moisture analysis of lyophilized allergenic extracts.

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.

Allergens↗

Stability of antigen E in commercially prepared ragweed pollen extracts.

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.

Aluminum↗

Modification of the microtiter technique for antimicrobial drug susceptibility testing by incorporation of indicators.

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.

Anti-Bacterial Agents↗