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Biomedical subjects

J C Adams

Publications and source records attributed to J C Adams.

108 records · Page 6Linked to original sources
PubMed1976

Single unit studies on the dorsal and intermediate acoustic striae.

Studies were made of the fiber compositon and of single unit dischage characteristics in the dorsal and intermediate acoustic straie. Counts of fibers and cells revealed more than twice as many fibers as cochlear nucleus cells of the types known to contribute axons to these tracts. Recordings were made in the striae to confirm the classes of discharge patterns which are transmitted from the posterior cochlear nucleus to more central structures and to seek evidence for descending activity entering the cochlear nucleus through the striae. Discharge patterns of the majority of units resembled those seen in previous studies when recordings were made from regions of the cochlear nucleus which are known to contribute fibers to the striae. Some patterns, however, were unlike any which have been reported in the cochlear nucleus on the same side as the recording site, but resembled activity of other auditory structures, suggesting that these were descending inputs. To confirm the presence of descending activity, recordings were made in the dorsal acoustic stria at a point medial to where the stria had been completely severed. Recordings made under these conditions demonstrated the presence of descending activity. The physiological findings help explain the disparity between the counts of fibers and cells, and point out a need for more detailed descriptions of the origins of descending inputs through the striae.

Acoustic Stimulation↗
PubMed1976

Origins of axons in the cat's acoustic striae determined by injection of horseradish peroxidase into severed tracts.

Origins and terminations of fibers of the dorsal and intermediate acoustic striae were studied by surgically severing these tracts and injecting HRP into the incision. This procedure results in filling the severed axons with HRP. Filled axons were traced to cell groups of origin and to some terminations of the acoustic striae. HRP-labeled terminals were found in the cochlear nuclei as well as in periolivary cell groups. Filling of cells with HRP RANged from being complete, resulting in Golgi-like images, to being barely detectable. Labeled cells were abundant in the dorsal and posteroventral cochlear nucleus adjacent to the injection as well as scattered throughout the periolivary cell groups of both sides, being highest in concentration around the ipsilateral lateral superior olive. On the side contralateral to the injection, labeled cells were found along the medial border of the dorsal cochlear nucleus, in the interstitial nucleus of the stria of Held, and sparsely throughout the ventral cochlear nucleus. The distribution of labeled cells was similar following HRP injections of the dorsal cochlear nucleus, except that these injections revealed additional descending projections from the inferior colliculi and from the ventral nucleus of the trapezoid body of both sides. These additional projections were interpreted as entering the CN by a ventral route. Findings of this study are in accord with physiological recordings made from fibers of the acoustic striae.

Afferent Pathways↗
PubMed1975

A veterinary-controlled meat and poultry inspection centre in Canada.

After being awarded a Sir Winston Churchill Fellowship the author visited Canada to examine the meat and poultry industry, particularly methods of production, inspection and retailing. This article deals with the methods of meat and poultry inspection employed in Canada's meat and poultry processing plants.

Animals↗
PubMed1975

Identification of a novel cell type in peripheral lymphoid organs of mice. IV. Identification and distribution in mouse spleen.

White pulp nodules of mouse spleen contain a minor population of cells with morphologic features that are identical to those of dendritic cells, a cell type recently described in vitro. They have characteristic large, irregularly shaped nuclei with distinctive chromatin patterns and small nucleoli. The cytoplasm is extended in processes that contain relatively few organelles. These presumptive dendritic cells can be distinguished from other cell types that are known to exist in spleen including those that have irregular or branching cell shapes. In particular, dendritic cells do not contain the large number of lysosomes seen in phagocytes, and do not actively interiorize intravenously administered colloidal thorium dioxide particles. They also lack the well developed secretory apparatus (rough endoplasmic reticulum and Golgi zone) and microfilament bundles that are noted in connective tissue cells. These morphologic observations, combined with previous in vitro work, substantiate the existence of a novel class of cells in mouse lymphoid organs.

Animals↗
PubMedDate not supplied

Prospects for immunocytochemical studies of the labyrinth.

Immunocytochemistry, when used with traditional and other modern techniques, offers great promise as a tool for cytochemically characterizing cells and their processes in the normal and pathological labyrinth. The strength of assertions regarding results of such studies is proportional to the degree to which antibodies are characterized, a limitation that has often been neglected in studies of the labyrinth. Examples are given to demonstrate the degree of species variability of cytochemically distinct efferent fibers in the cochlea, and to demonstrate how readily new information can be obtained when appropriate antibodies are available.

Animals↗