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K Addicks

Publications and source records attributed to K Addicks.

At least 109 records · Page 6Linked to original sources
PubMed1982

The paraganglion supracardiale vagi: an intravagal paraganglion in the rat.

In the Ham-Wistar rat, a paraganglion was found within the vagus nerve at the site of branching of the recurrent laryngeal nerve. Due to its location the name "paraganglion supracardiale vagi" is suggested. Fluorescence microscopy of the paragangkionic cells displays an intense yellow-green fluorescence indicating the presence of biogenic amines. Ultrastructurally, chief cells containing dense-core vesicles form three kinds of synaptic contacts (afferent, efferent and reciprocal) with enlarged. mitochondria-rich nerve endings.

Amines↗
PubMed1982

Formation of perichromatin granules, nematosomes and concentric lamellar bodies in sympathetic postganglionic perikarya in response to immobilization stress.

Perichromatin granules, nematosomes (threadlike bodies), or concentric lamellar bodies were rarely observed in profiles of principal ganglionic neurons in the untreated rat superior cervical ganglion. They were more frequently encountered in these neurons following long-term activation of the sympathetic nervous system by intermittent immobilization (6 to 18 12-h periods). The increased number of the described nuclear and cytoplasmic structures following immobilization is documented by morphometric data and discussed in relation to specific chronic neuronal hyperactivity.

Animals↗
PubMed1980

Ultrastructure of baroreceptors in the carotid sinus of the rabbit.

In the rabbit, baroreceptive intercalated and terminal receptor segments of the sinus nerve extend in the border region of adventitia and media of the carotid sinus wall. these receptors measuring 600-6,500 nm harbour a great number of mitochondria. They are either round, avoid or elongated. Round receptors are present over the whole area of the carotid sinus. Large receptors appear to be missing in the upper region, where only very elongated receptors are present, which are arranged in circular array in relation to the vascular axis. The baroreceptors are enveloped by special organelle-rich terminal cells of Schwann cell origin. The receptors have a special orientation in regard to the muscle-elastic system and to collagen. Receptors contain osmiophilic and laminated bodies, signs of degeneration and vesicles of different sizes. Many tubuli as well as glycogen granules are apparent. Some of these axoplasmatic changes appear to be related to metabolic processes (turnover) occurring in young and old animals.

Animals↗
PubMed1980

Catecholamines in paraganglionic cells of the rat superior cervical ganglion: functional aspects.

In the rat SCG two types of paraganglionic cells have been identified immunohistochemically in a ratio of about 5% DBH-positive to 95% DBH-negative cells. Measurements of CAs in SIF cell clusters separated from principal neurons with the microlaser and using the technique of quantitative mass fragmentography disclosed the presence of E within paraganglionic cells, thus confirming the proposal that, besides DA, E also is stored in most cells. Following immobilization of adult rats, the majority of SIF cells revealed a time-dependent loss of formaldehyde-induced fluorescence intensity that could be ultrastructurally correlated with an increasing degranulation of small granule-containing perikarya, presumed to store DA and E. Similar results were obtained in type I cells of the rat carotid body and adrenal medullary cells, thus suggesting a mutual endocrine function. An additional interneuronal mode of modulation is assumed, since degranulated cells are capable of displaying efferent synaptic contact with postganglionic neurons. A minor cell population, storing granular vesicles similar to those in the NE-containing cells of the adrenal medulla, did not respond with degranulation to functional strain of the vegetative nervous system. Our results strongly corroborate the hypothesis that a functional dualism exists: Most paraganglionic cells can act as an interneuron and as an endocrine cell.

Animals↗
PubMed1977

[The fine structure of baroreceptor's nerve endings in the wall of carotid sinus in cats].

The baroreceptor endings of the sinus nerve extend into the region of the external media, to the media-adventitia border, and into the adventitia of the wall of the carotid sinus. The size of the receptors, tightly filled with mitochondria, varies between 600 and 5,700 nm in diameter. The endings are accompanied by densely structured Schwann's cells, come into contact with the muscular-elastic system or are surrounded by the collagenous material of the vessel wall. This functional junction makes the reception of the tension in the vessel wall possible. Glycogen granules could be demonstrated in some axon endings. In kittens and older cats, numerous receptors were regularly found with various degrees of structural change: homogeneous and lamellar transformation of mitochondria, lamellar aggregates, lysis of axoplasm matrix, irregularities of tubules and vesicles. These modifications may be evaluated as the morphological expression of degeneration and regeneration processes. Physiological detrition is considered to be the cause for this.

Age Factors↗
PubMed1976

Electron microscopic studies of the pressoreceptor fields of the carotid sinus of the dog.

In the dog, pressosensitive endings of the sinus nerve extend along the border between the adventitia and media of the carotid sinus wall. The axon endings, containing a great number of mitochondria, can be divided into small (600-2,000 nm) and large (6,000-8,000 nm) end swellings. In the terminal region the pressosensitive fibers are surrounded by ramified and highly structured Schwann "terminal cells". The topographic location in relation to elastic and collagenous tissue indicates a functional connection between receptors and efferent nerve endings in the immediate surroundings has been discussed in this report. Several axon endings contain variable amounts of glycogen which is regarded as an indication for the inactive metabolic state of the ending. Axonal swellings demonstrate considerable modification in structure, such as loss of structural integrity in mitochondria, the formation of lamellar fields, vesicular irregularities and disintegration of axoplasm, all of which are considered as the morphological expression of "wearing out", degeneration and possibly regeneration.

Animals↗
PubMedDate not supplied

Fibrosis adjacent to the anterior lens capsule after extracapsular cataract extraction.

Fibrosis, contraction and opacification of the posterior lens capsule after extracapsular cataract extraction, is a frequent complication following cataract surgery. In these cases, cellular proliferation occurs along an intact posterior capsule. We report a case of fibrosis adjacent to the anterior lens capsule, where cellular proliferations and collagen production completely sealed the anterior capsulotomy three months after a routine extracapsular cataract extraction with implantation of a posterior chamber lens. The fibrosis led to contraction of the remainder of the anterior capsule, significantly reducing vision. Examination of the excised material by light and electron microscopy, and immunohistochemistry, revealed cells with features compatible with fibrocytes that did not stain positive for cytokeratin. The cells were situated in a dense collagen matrix. An anterior capsulotomy that is too small prevents sufficient removal of lens epithelium, and may be a risk factor for this complication.

Aged↗
PubMedDate not supplied

Acute myocardial ischaemia in the anaesthetised pig: local catecholamine release and its relation to ventricular fibrillation.

In anaesthetised open-chest pigs, sequential myocardial samples were obtained before and after occlusion of the distal half of the LAD. These samples were analysed histofluorimetrically to determine the density of catecholamine containing neurones in each sample (quantified morphometrically), and radioenzymatically for total tissue noradrenaline content. Following coronary artery occlusion, 75% of the animals (24 out of 32) died in ventricular fibrillation in the first 30 min, the other 25% (8/32) survived the first 60 min of myocardial ischaemia. Coronary artery occlusion led to a significant reduction in the density of fluorescing fibres in the ischaemic myocardium of animals which fibrillated (from 1.25 +/- 0.2% to 0.67 +/- 0.10% at 15 min) whereas in the survivors there was no significant change in fluorescing area during the course of the experiment. Animals which fibrillated had a significant reduction in tissue noradrenaline concentration of the ischaemic myocardium (from an initial concentration of 612 +/- 72 to 402 +/- 64 ng/g ww) within the first 5 min of ischaemia. It is concluded that in this model of myocardial ischaemia, the development of ventricular fibrillation in the early phase seems to be related to the release of noradrenaline from the sympathetic neurones after the onset of myocardial ischaemia.

Animals↗
PubMedDate not supplied

Embryonic stem-cell derived neurones express a maturation dependent pattern of voltage-gated calcium channels and calcium-binding proteins.

There are remarkable changes of calcium binding proteins and voltage dependent Ca(2+) channel subtypes during in vitro differentiation of embryonic stem cell derived neurons. To observe these maturation dependent changes neurones were studied using combined immunohistochemical, patch clamp and videomicroscopic time lapse techniques. Embryonic stem cell derived neuronal maturation proceeds from apolar to bi- and multipolar neurones, expressing all Ca(2+) channel subtypes. There is, however, a clear shift in channel contribution to whole cell current from apolar neurones with mainly N- and L-type channel contribution in favour of P/Q- and R-type participation in bi- and multipolar cells. Expression of the calcium binding protein parvalbumin could be detected in bipolar, while calretinin and calbindin was preferentially found in multipolar neurones. Our data provides new insights into fundamental neurodevelopmental mechanisms related to Ca(2+) homeostasis, and clarifies contradictory reports on the development of Ca(2+) channel expression using primary cultures of neurones already committed to certain brain compartments.

Animals↗
PubMedDate not supplied

[Histologic, morphometric study of the human synovial membrane].

Human synovial membrane was studied by light- and electronmicroscope and histomorphometrically. Areas of distinct structures are seen. The surface structure fold that is mainly seen in the areaolar and adipose synovial membrane type, seemed to be the prime structure for the synovial turn over. Villi have fenestrated capillaries and they are covered of A- and AB-synoviocytes. Villi are regarded as the synovia production areas. The fibrous type of the synovial membrane is mostly smooth surfaced and seemed to be an ordinary fibrous connective tissue. The B-synoviocyte is discussed as fibrocyte.

Adult↗