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Biomedical subjects

L Hankin

Publications and source records attributed to L Hankin.

At least 19 recordsLinked to original sources

An examination of enzyme production of Phytophthora spp. on solid and liquid media.

Solid media were used to determine which extracellular hydrolytic enzymes are produced by Phytophthora parasitica; P. parasitica var. nicotianae, races 0, 1, and 3; and several other Phytophthora spp. Most isolates produced RNase, DNase, phosphatase, lipase, and cellulase uniformly. All race 3 isolates of P. parasitica var. nicotianae exhibited protease activity on a medium containing gelatin, while only 33 and 60% of the race 0 and 1 isolates, respectively, and 14% of the P. parasitica isolates did so. Addition of sorbose to this medium enabled the detection of protease activity by most of the isolates. Amylase activity, measured in the culture fluid, was higher in race 3 than in races 0 or 1 of P. parasitica var. nicotianae and P. parasitica.

Culture Media↗

Solid media containing carboxymethylcellulose to detect CX cellulose activity of micro-organisms.

Solid media containing carboxymethyl cellulose (CMC) were developed to detect CX cellulose-producing micro-organisms. Hydrolysis of CMC was seen as a clear zone around colonies after flooding plates with 1% aqueous hexadecyltrimethyl-ammonium bromide. Tests with ten bacterial and four fungal species showed that the degree of substitution (DS) of the CMC affects both growth and enzyme production. Most of the organisms produced more CX cellulase on CMC with a DS of 0-9, but CMC with a DS of 0-4 was better for one fungus. A qualitative measure of cellulase production may be obtained by calculating the ratio of zone size to colony diameter. Solid media containing CMC provided a more rapid assay of CX cellulose production than a medium containing native cellulose.

Actinomycetales↗

Production of Kestoses (Fructosylsucroses) by Phytophthora parasitica var. nicotianae.

The synthesis of kestoses (trisaccharides composed of two fructose units and one glucose unit) by races 0 and 1 of Phytophthora parasitica var. nicotianae is shown. The trisaccharide is found in culture filtrates of isolates grown in liquid media containing 3% sucrose. The utilization of sucrose and trisaccharide formation by the organisms over a 16-day period is described. The kestoses were identified by chemical and enzymatic analysis, and two of three possible isomers were found.

Journal Article↗

Lead on painted handles of kitchen utensils.

The lead content of paint on wooden handles of kitchen utensils ranged from 0 to 9.7 per cent (97,000 ppm). Yellow paint showed the highest concentration of lead followed by green and red colors. The values of lead often exceeded the legal limit on toys and paint for use indoors.

Cooking and Eating Utensils↗

Lead in pet foods and processed organ meats. A human problem?

The finding that canned pet foods contain considerable amounts of lead is important, since it had been alleged that some of these products are used for human consumption. The lead content of canned dog and cat food ranged from 0.9 to 7 ppm, and ingestion of 170 gm (6 oz) could provide up to 0.95 mg of this toxic element. The lead probably comes from organ meats used in the manufacture of pet foods. The lead content of liverwurst ranged from 1.6 to 7.6 ppm.

Age Factors↗

Bacteria in enucleated prostate.

The controversial nature of prostatitis is compounded by questions concerning the incidence and significance of bacteria within the prostate. Criticism of bacteriologic studies of expressed prostatic secretion, ejaculate, needle biopsy, and transurethral chips led us to culture the core of enucleated prostates. Of 65 prostates, 26 (40 per cent) were positive: 15 pathogens (23 per cent) and 11 nonpathogens (17 per cent). This was correlated with preoperative urinary infections, anterior urethral infection, and postoperative infectious complications. Prostatic pathogens were usually found when the urine and anterior urethra were infected.

Bacteria↗