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Biomedical subjects

C Cook

Publications and source records attributed to C Cook.

At least 91 records · Page 5Linked to original sources

Morphologic changes induced by photoperiod in eyes of turkey poults.

Large White commercial tom poults were grown from 1 day to 8 weeks of age in the following light treatments: (i) continuous incandescent light (24LL); (ii) 23 hours of incandescent light and 1 hour of darkness/day (23L:1D); (iii) 12 hours of incandescent light and 12 hours of darkness/day (12L:12D); or (iv) natural decreasing day lengths (natural). At 8 weeks of age, significant (P less than 0.05) morphologic changes in eyes occurred. Poults exposed to the 24LL or 23L:1D had heavier eyes than did poults exposed to the 12L:12D or natural day length. In addition, the eye size (anterior to posterior diameter and horizontal width) exposed to the 24LL treatment was greater than those exposed to 23L:1D, 12L:12D, or natural day length. Cornea heights of poults exposed to 24LL or 23L:1D were smaller than cornea heights of those exposed to 12L:12D or natural day length. Marked differences did not occur in intraocular pressure among treatments.

Animals↗

Effect of microwave energy on the metabolism of Enterobacteriaceae.

The effect of microwave irradiation on the metabolism of 94 strains of Enterobacteriaceae was studied. Sixteen substrates were used and the results obtained with microwave irradiation were compared with those given by conventional biochemical tests. There was good correlation between the methods but not sufficient to enable accurate identification of unknown species. However, microwave irradiation considerably increased the enzymatic activity of bacterial suspensions and the results obtained could form the basis for a rapid method of microbial identification.

Carbohydrate Metabolism↗

Electron transfer across the chromaffin granule membrane.

Membrane vesicles (ghosts) containing ascorbic acid were prepared from bovine chromaffin granules. When ferricyanide or ferricytochrome c were added to the external medium, a membrane potential (interior positive) developed across the ghost membrane. This membrane potential could not be elicited from ascorbate-free ghosts or by ferrocyanide added instead of ferricyanide. These results indicate that the chromaffin-granule membrane has a transmembrane electron carrier with a midpoint potential between that of ascorbate (+85 mV) and that of cytochrome c (+255 mV). The most likely candidate is cytochrome b-561 (+140 mV).

Adrenal Medulla↗

Allergic granulomatous nodules of the eyelid and conjunctiva. The XXXV Edward Jackson Memorial Lecture.

We studied the clinical and pathologic features of 22 cases of granulomas of the conjunctiva or eyelids. All cases showed the histologic features of the Splendore-Hoeppli phenomenon, that is, a giant cell and eosinophil granulomatous reaction to an antigen-antibody precipitate originally described in relation to parasites or fungi. In four of seven typical cases selected for detailed description unidentified nematodes were found to be the cause of the condition. In light of these findings together with a review of similar "allergic granulomas" reported both in ocular tissues and elsewhere in the body, we considered the cause in the remaining cases. All 22 cases may have been caused by nematodes, as seems, probable in 14 of them, or the causative antigens may have been of widely different kinds. Although in our cases all ocular granulomas had an identical histology, this study did not resolve the problem of those cases where no causative agent was found. Thorough investigation of such cases in the future and the demonstration of their cause may elucidate the wider problem of nonocular allergic granulomas.

Adolescent↗

XXXV Edward Jackson Memorial Lecture. Allergic granulomatous nodules of the eyelid and conjunctiva.

Twenty-two cases of granulomas of the conjunctiva or eyelids were studied, and the clinical and pathologic features were tabled. All cases showed the histologic features of the Splendore-Hoeppli phenomenon, that is a giant cell and eosinophil granulomatous reaction to an antigen-antibody precipitate originally described in relation to parasites or fungi. Seven typical cases were selected for detailed description; in four of these cases, unidentified nematodes were the cause of the condition.

Adolescent↗

Encephalitozoonosis (nosematosis) causing bilateral cataract in a rabbit.

Bilateral cataract due to a microsporidan believed to be Encephalitozoon cuniculi (also called Nosema cuniculi) is described as an incidental finding in a laboratory rabbit. The route of infection and the significance of the findings are discussed. This is apparently the first report of cataract due to this cause.

Animals↗