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C A Ackerley

Publications and source records attributed to C A Ackerley.

29 records · Page 2Linked to original sources
PubMed1991

Expression of the cystic fibrosis gene in non-epithelial invertebrate cells produces a regulated anion conductance.

The nature of involvement of the cystic fibrosis gene product (CFTR) in epithelial anion transport is not yet understood. We have expressed CFTR in Sf9 insect cells using the baculovirus expression vector system. Reactivity with antibodies against 12 different epitopes spanning the entire sequence suggested that the complete polypeptide chain was synthesized. Immunogold labeling showed localization to both cell-surface and intracellular membranes. Concomitant with CFTR expression, these cells exhibited a new cAMP-stimulated anion permeability. This conductance, monitored both by radioiodide efflux and patch clamping, strongly resembled that present in several CFTR-expressing human epithelial cells. These findings demonstrate that CFTR can function in heterologous nonepithelial cells and lend support to the possibility that CFTR may itself be a regulated anion channel.

Animals↗
PubMed1991

Structure-function relationships during preovulatory development of porcine follicles following equine chorionic gonadotropin stimulation.

Porcine follicular maturation begins by recruitment from a continually proliferating pool of small antral follicles; those receiving the appropriate stimulus differentiate rapidly through a series of structural and functional changes. Such ovarian activity can be induced in prepubertal gilts with a single injection of equine chorionic gonadotropin (eCG). Average follicular diameter in eCG treated females increased from approximately 2 mm before stimulation to 3.5 mm by 24 hr after injection, with subsequent growth to ovulatory size (8 or 9 mm) by 96 hr. Both theca and granulosa layers increased in thickness and complexity, and a prominent capillary bed evolved immediately outside the basement membrane separating the two layers. Cytoplasmic organelles associated with increased metabolic activity and steroidogenesis proliferated within the first 24 hr. Progressive changes included increasing amounts of lipid and rough and smooth endoplasmic reticulum, with the latter occurring in vesicular or lamellar forms and as lipid-associated whorls. Bizarre mitochondrial forms also appeared, often associated with lipids. The amount and proportion of rough and smooth endoplasmic reticulum shifted dramatically as follicles matured. By 24 hr, rough endoplasmic reticulum in thecal cells increased from 4.2 to 7% of cell volume, while the amount in granulosa cells increased from less than 3.5% to more than 10%; the quantity remained relatively constant in the theca but declined to prestimulation values in the granulosa layer. Rough endoplasmic reticulum predominated over smooth in the first 24 hr following stimulation but the proportions were then reversed, so that more than 10% of both layers was composed of smooth endoplasmic reticulum by the time ovulation was imminent. Some follicles had or were in the process of ovulating by 96 hr. Their walls were collapsed into prominent folds with the two cell types beginning to mix. Slight undulations and some regions of discontinuity were observed in basement membranes of large unovulated follicles at this time. In specimens collected at 96 hr poststimulation and processed for retention of lipid, lipid-like material was noticeable in the extracellular matrix surrounding cells that contained organelle configurations suggestive of steroidogenesis.

Animals↗
PubMed1991

Localization of CD44 (P80) on the external surface of a human astrocytoma cell.

A brain antigen, originally identified by a MAb 44D10, has been shown to be a glycoprotein with an Mr of 80 kDa. Cellular localization studies of sections of brain showed that the antigen was associated with the membrane of astrocytes. In the present study we demonstrate its localization to the membrane of an astrocytoma cell line by fluorescence and electron microscopic immunogold methods. Heavy labelling with immunogold was found along cellular processes. Labelling of the smooth surfaces of cells and the microvilli was also observed.

Antibodies, Monoclonal↗
PubMed1987

The use of silver nitrate staining and backscattered electron imaging to visualize nematode sensory structures.

Parasitic nematodes of the species Cosmocercoides variabilis were stained with silver nitrate and examined with backscattered electron imaging (BEI). Sensory papillae were selectively highlighted in backscatter images. Silver stain deposited on papillae was located on the papillary surface as well as on the underlying dendritic process. Portions of the body cuticle were also stained. Some cuticular staining was attributed to non-specific deposition of silver but, consistent patterns of cuticular staining were noted in the anterior and posterior regions. This observation suggests that some staining of the cuticle was specific. Results of this preliminary work suggest that BEI is a technique useful to the study of nematode form.

Animals↗
PubMed1985

Demonstration of oestrogens in developing pig trophectoderm and yolk sac endoderm between days 10 and 16.

Segments of individual blastocysts collected on Days 10, 12, 14 and 16 were examined microscopically to observe yolk-sac development and treated immunocytochemically to localize oestrogens in specific membranes. Mesoderm was present beneath the embryonic disc of ovoid blastocysts on Day 12. The mesoderm spread beyond 1 cm from the disc on Day 14, producing a splanchnic yolk-sac membrane extending across the blastocoelomic cavity, but no mesodermal cells had yet reached 5 cm. By Day 16, proliferation of mesoderm and development of the yolk sac had progressed beyond 20 cm from the disc in most of the specimens examined. Incubation of ultrathin sections with sheep antiserum to oestrone or oestradiol-17 beta followed by rabbit anti-ovine IgG-gold complex and subsequent counting of gold particles retained over the tissues gave a weakly positive reaction for oestrone in trophectodermal cells on Day 10. The most intense reaction for oestradiol-17 beta was also present in the trophectoderm and yolk-sac endoderm on Days 12, 14 and 16.

Animals↗
PubMed1985

Copper-induced myopathy in rabbits: ultrastructural observations.

Mature rabbits were injected intra-muscularly into the hamstring (HS) muscles with doses of 1.66 mg Cu/kg/day, as cupric acetate, in aqueous solution. Similar doses of Na acetate were injected into control rabbits. Skeletal (HS) and cardiac (MYO) muscles were examined by scanning electron microscopy, transmission electron microscopy and a microanalyzer and energy dispersive X-ray (MEDX). Na-injected rabbits showed slight myofibrillar lesions in HS after four injections, and mitochondrial inclusions in MYO were noted after two or seven injections. No Cu was found with MEDX. Cu-injected rabbits showed that the severity of lesions of myofibrillar degeneration and mitochondrial inclusions in HS increased with the number of injections and days the rabbits had been on experiment. After seven days on experiment signs of muscle regeneration were seen. Cu was found first to localize in the nucleus of HS after one day, thereafter it localized in the mitochondria after three and seven days. MYO lesions were found in the mitochondria after six or seven days after Cu-injection. With MEDX less Cu was found than had been found in HS. This Cu first localized in the nucleus of MYO after one day and then disappeared from the tissue altogether.

Animals↗
PubMed1980

Scanning electron, light optical, and transmission electron microscopy and plasma steroid values of porcine uterus at lactation.

Sows, while nursing litters for a period of 4 to 8 weeks, do not ovulate, thereby delaying the time sows can be rebred. Therefore, this study sought to determine how soon after parturition the morphological appearance of the uterus was such that blastocyst implantation could possibly proceed. Biopsy samples taken immediately post-partum and on days 1, 2, 3, 4 post-partum show that the endometrium was considerably damaged as evidenced by sloughing of the zona compacta and zona spongiosa and the presence of leukocytes around the surface epithelial (SE) cells. Around the 6th day post-partum the numbers of leukocytes were reduced and regeneration of the SE was evident. Around the 8th day post-partum, SE cells appeared similar to those of normal cyclic sows in the late luteal phase (i.e. 15 days post-estrum). Under normal breeding conditions, blastocyst implantation takes place during the late luteal phase. From 17 to 26 days post-partum the SE cells appeared similar to those of normal cyclic sows in the early follicular phase (i.e. 21 days post-estrum), and the subepithelial layers seemed edematous. Estradiol and progesterone concentrations dropped markedly at parturition and remained low up to the 26th day of lactation. Although there was considerable heterogeneity of samples between sows it was concluded, from the morphological results, that plasma steroid levels exert relatively little effect on the sow endometrium up to 26 days post-partum. If ovulation could be induced or ova transplant be performed in lactating sows the endometrium would appear ready for blastocyst implantation after day 8 post-partum.

Animals↗
PubMedDate not supplied

Tuberin expression in ganglioglioma.

The expression of tuberin in neurosurgically resected gangliogliomas was investigated. Neither neoplastic astrocytes nor abnormal, multipolar large neurons showed immunoreactivity for tuberin. The reduced immuno-histochemical staining for tuberin was consistent with the reduction observed in Western blot analysis. Eosinophilic granular bodies and Rosenthal fibers were strongly immunoreactive for tuberin. The accumulation of tuberin in astrocytes with intracellular degenerative changes suggests increased expression in reactive cells, and perhaps a broader role for tuberin in central nervous system disease.

Adolescent↗
PubMedDate not supplied

Correlative light optical, scanning electron, and transmission electron microscopy of skeletal muscle in muscular dystrophy and muscular atrophy: a pilot study.

Biopsies of skeletal muscle from three different cases of muscular dystrophy and one case of spinal muscular atrophy that has been fixed with Karnovsky's fluid were either routinely prepared for scanning electron microscopy (SEM) or were frozen to -20 degrees C and sectioned on a steel knife in a cryostat at 5-10 micrometer. The sections were coverslipped and examined using a light microscope equipped with polarizing optics (Pol). After areas were selected, the sections were prepared for SEM and thereby examined. The tissues on the slides that had been observed with light microscopy (LM) and SEM were prepared further for transmission electron microscopy (TEM) by infiltrating them with Epon and cutting sections at approximately 100 nm on an ultramicrotome. It is shown that the stage of contraction in one pathologic myofiber may vary along its length. The following advantages may be realized by using correlative (Pol leads to SEM leads to TEM) microscopy on skeletal muscle biopsies: 1) lesions can be differentiated from "normal" surrounding tissue; 2) doubtful structures can be reexamined with the SEM and TEM; and 3) the SEM image of different states of muscle contraction can be reinterpreted in the light of the Pol or TEM image.

Adolescent↗