Search PubMed⌕ Search

Biomedical subjects

M Anniko

Publications and source records attributed to M Anniko.

At least 181 records · Page 10Linked to original sources
PubMed1980

Embryogenesis of the mammalian inner ear. III. Formation of the tectorial membrane of the CBA/CBA mouse in vivo and in vitro.

The development of the tectorial membrane in the basal coil of the cochlea has started already in the 15th gestational day inner ear and has reached a considerable thickness and maturation at birth. The development of the tectorial membrane occurs synchronously in in vivo labyrinths and the in vitro material cultured to an age corresponding to birth. At least during this part of the development the formation of the tectorial membrane is independent of the specific composition of endolymph. In the in vivo material a secretory maximum was reached on the 18th gestational day, whereafter the secretory activity was low, especially after birth. In the in vitro specimens, however, a rather constant secretion of material occurred also post partum, which indicates a lack of control mechanisms during in vitro conditions. A complete maturation of the tectorial membrane did not occur in vitro. When passing the point of time corresponding to birth, in the in vitro inner ear explants the gross structure of the tectorial membrane is only slightly changed. In vivo a mature configuration of the tectorial membrane is observed on the 14th DAB (day after birth).

Animals↗
PubMed1980

Vestibular hair cell pathology in the Shaker-2 mouse.

The circling-waltzing behaviour of the Shaker-2 mouse is suggested, at least in part, to be of peripheral origin. In this hereditary inner ear disease, degeneration of hair cells type I has been observed showing specific pathologic features: rod-shaped inclusion bodies and sensory hair fusion. Later, the hair cells type I are expelled into the endolymphatic space. A large number of sensory cells type II are morphologically normal. The failure of earlier investigators to demonstrate pathological changes in the sensory epithelia of this animal is likely to be due to the use of light microscopical methods only.

Animals↗
PubMed1980

Embryogenesis of the inner ear. IV. Post-natal maturation of the secretory epithelia of the inner ear in correlation with the elemental composition in the endolymphatic space.

The rise of the potassium concentration in the endolymphatic space occurred between the 4th and 8th day after birth (DAB). During this time morphological maturation of the stria vascularis was ended. The increasing concentration of potassium in the developing endolymph parallelled in the vestibular and cochlear parts of the labyrinth. The dark cell epithelium surrounding vestibular organs was, however, ultrastructurally mature at birth except for an increase of the number of intercellular digitations toward the basal membrane maturing during the first days postpartum. The maturation of endolymph thus took place prior to the development of the endocochlear potential.

Animals↗
PubMed1980

Development of otoconia.

The development of the majority of otoconia in the macula utriculi occurs on the fifteenth and sixteenth gestational days (CBA/CBA strain of mice). The epithelial cell layer shows extensive protrusion of some cells, cytoplasmic blebbing from the surface of both hair cells and supporting cells, and electron dense inclusion bodies and vesicles surrounded by a double membrane in the apical part of supporting cells. This may reflect the formation of otoconia of varying sizes. Otoconia have an organic matrix that often shows a fibrillar substructure early in development. The majority of the organic aggregations that probably become the future otoconia are surrounded by a limiting membrane. The hexagonal shape of the otoconia can be observed as early as the sixteenth to seventeenth gestational days. Some otoconia show a nucleus-like focus in the center of the organic substance. Elemental mapping of calcium on the sixteenth gestational day shows an accumulation of calcium not only in the otoconia but also in the apical part of the epithelia cell layer below the otoconia. The endolymphatic space does not contain much calcium. These findings indicate that during the incorporation of calcium into otoconia, calcium is likely to emanate largely from the surface cells of the utricle.

Animals↗
PubMed1980

Sensorineural hearing loss in a Scandinavian old English sheepdog. A case report.

Inner ear disease is extremely rare in the old English sheepdog. The present case would constitute the second known case in Scandinavia and the first one observed in Norway. The morphological investigation revealed complete degeneration of the organ of Corti. A single layer of cells was covering the anatomical location of the stria vascularis. The dog did not show clinical signs of vestibular dysfunction. Hair cells were present in the cristae ampullares and macula utriculi. The histopathological features support a genetic basis for the sensorineural hearing loss, though other (rare) causes of exogenically induced inner ear degeneration cannot be completely excluded on the morphological findings alone. The brain revealed signs of chronic meningitis.

Animals↗
PubMed1980

Embryologic development in vivo and in vitro of the dark cell region of the mammalian crista ampullaris.

The area comprising the dark cells around vestibular organs was analysed with regard to embryologic development and maturation from the 13th gestational day (otocyst stage) (CBA/CBA mouse) to birth at the 21st gestational day when the organ reveals a morphologic maturation of inner ear gross structure and as also cytodifferentiation of vestibular hair cells. The development occurred parallel in vivo and in vitro. Electron-optically dense pigments below the dark cell region were first identified on the 15th gestational day. On the 16th gestational day the future dark cells have their mitochondria accumulated to the infranuclear region of the cell. From the 17th day onward, intercellular spaces develop close to the basal membrane, forming at birth a meshwork of interdigitations. Prior to birth the future dark cells reveal an increase in electron density after staining. At birth the morphological configuration of the dark cell area appeared quite mature.

Animals↗
PubMed1980

Growth hormone and prolactin production in human pituitary tumours in organ culture.

Human pituitary adenomas, when preserved as organ cultures do not lose their function of synthesizing and releasing hormone. Thus, growth hormone producing adenomas have been cultured for 35 days and prolactinomas for 14 days with maintained hormone hypersecretion, > 30 000 pmol/l/48 h of growith hormone and > 15 000 micrograms/l/48 h of prolactin. Preserved morphology/ultrastructure was documented in these specimens. Following repeated renewal of the entire nutrient solution, less than 1/10 of the initial hormone content remained after the first change, indicating an active hormone production/release into the culture medium as hormone concentration rose to previous levels. The growth hormone producing cells could be stimulated by TRH and LH-RH in the concentrations 10(-8) and 10(-7) g/l respectively, indicating the same pathological reactivity in vitro as in vivo. Prolactin synthesis in vitro paralleled that in vivo, as reflected by serum prolactin levels. Growth hormone synthesis in vitro paralleled the clinical activity of the disease, but the plasma hormone levels in patients with acromegaly did not do so.

Adenoma↗
PubMed1980

[Surgical management of pituitary adenomas with preservation of pituitary function (author's transl)].

Tumors of the pituitary gland comprise a large group of the intracranial tumors. As in all tumor surgery, early diagnosis is essential for the best outcome of treatment. However, the non-functioning adenomas are often diagnosed in their later stages of development as a result of the complexity of symptoms due to a mass lesion. In contrast, hormone-secreting adenomas give early symptoms which can be supported by reliable diagnostic laboratory findings and involve the production of growth hormone, prolactin and ACTH respectively. Using the transantro-sphenoidal route, our results of surgical removal of small tumors have been excellent, and microadenomas have been treated with preservation of normal pituitary function. However, an increasing size of the tumor considerably reduces the possibility of cure.

Adenoma↗
PubMed1979

The inner ear and the in vitro system.

The embryologic labyrinthine development of the CBA/CBA mouse occurs parallell in vivo and in vitro. Regarding post partum inner ears, either as cultured otocysts passing a corresponding time in vitro or inner ear explants of newborn/mature animals, the extracorporal system becomes unable to maintain specialized hair cell structures for more than a few days. The sensory cells themselves, however, survive for considerably longer time. Vestibular hair cells show sensory hair fusion. Cochlear hair cells loose their surface structures but the sensory hair rootlets penetrating into the cuticle are preserved. Post partum inner ears from the guinea pig reacted in a similar way in vitro as did labyrinths from the CBA/CBA mouse.

Animals↗
PubMed1979

Development of endolymph during maturation of the mammalian inner ear. A preliminary report.

The development of the elemental composition in the endolymphatic space was investigated during embryologic and early post natal maturation of the CBA/CBA mouse. At birth the elemental distribution was similar in the endo- and perilymphatic spaces. Mature composition of endolymph was reached 6--8 days post partum. The maturation of endolymph corresponded well in time with the morphological maturation of the stria vascularis.

Age Factors↗
PubMed1979

Human oral squamous cell carcinoma in in vitro culture.

Human biopsy specimens from squamous cell carcinomas in the oral cavity were explanted to an in vitro system for organ culture. Carcinoma cells in great number were observed after 2 weeks in vitro. A considerable variability in cell survival occurred after approximately 1 week. This period of time is, however, sufficient to perform experimental manipulation of the tumor tissue, e.g., testing of chemosensitivity, radiation effects, etc.

Carcinoma, Squamous Cell↗
PubMed1979

Genesis and maturation of vestibular hair cells.

The embryologic development in vivo and in vitro of mammalian hair cells in the crista ampullaris was continuously followed with regard to structural differentiation and maturation from the terminal mitosis to the morphological condition at partus or equivalent age in vitro. Otocysts were explanted both early and late during embryologic development: 13th and 16 gestation day, respectively. Both in fetal life and during in vitro conditions, the surface structures of the developing hair cell with regular arrangement of kinocilium/stereocilia were first differentiated, followed by a cytologic transformation intracellularly and subsequent development of nerve endings. Hair cells were able to develop without any morphologic contact with the nervous system. The afferent nerve system developed before the efferent nerve system (CBA/CBA mouse).

Animals↗
PubMed1979

Extracorporeal preservation. Organ culture of the post-natal mammalian inner ear.

Postnatal (newborn and mature) inner ear organs from CBA/CBA mouse and guinea pig were analysed concerning hair cell survival in an in vitro system. After only a few days in the artificial surroundings a transformation of hair cell characteristics occurred, in the form of either loss of sensory hairs (cochlear hair cells) or hair fusion (vestibular hair cells), although the hair cell itselt survived for a considerably longer time. Intracellular myelin figures became evident after 2--3 days in culture. However, a considerable individual variation among hair cells was observed concerning the ultrastructure of the cell at this stag in vitro. Completely normal hair cells could in rare cases be recognised after 1 week in organ culture (cochlear inner hair cells of the CBA/CBA mouse). Loss of the surface structures of the hair cells is likely to constitute an irreversible transformation not in agreement with the true hair cell characteristics.

Adaptation, Physiological↗
PubMed1979

In vitro preservation of human pituitary tumours in organotypic differentiation.

Three types of human pituitary adenomas--growth hormone producing, prolactin producing, as well as endocrinologically inactive ('chromophobe') tumours--were explanted to an in vitro system for organ culture. After one month, surviving hypophyseal cells demonstrated preserved hormone activity and no dedifferentiation of cell characteristics. During the first weeks in culture, close similarity existed between in vivo and in vitro conditions with regard to cell survival/cell morphology and physiological function/hormone release.

Adenoma↗
PubMed1979

Embryogenesis of the inner ear. I. Development and differentiation of the mammalian crista ampullaris in vivo and in vitro.

The embryonic development of the crista ampullaris in the CBA/CBA mouse was followed comparatively in vivo and in vitro after explanation of the 13th gestational day otocyst. Special attention was paid to hair cell differentiation. In general the in vivo and the in vitro groups of inner ears showed a similar morphological maturation of hair cells on the ultrastructural level. The first sign of hair cell differentiation occurred on the 14th day in vivo and after 1 day in culture showing a thickening of microvilli presumably indicating the development of future sensory hairs. On the 16th day or after 3 days of in vitro culture the sensory hairs were regularely arranged with the kinocilium located at the cell periphery. Afferent nerve endings were identified on the 17th gestational day and some nerve terminals were suspected to be of efferent character appearing on the 18th day. On the day of birth there did not occur complete nerve chalices but a differentiation of hair cells into type I and II was indicated on the 19th gestational day by a slight difference in hair cell configuration and extension of innervation.

Animals↗
PubMed1978

Bilateral reversible sudden deafness. A case report.

A man aged 43 suffering from acute bilateral sudden deafness of sensorineural type (confirmed at repeated testings) and without signs and symptoms from the vestibular part of the inner ear regained normal hearing within 10 days. The serological examination for identification of viral antibodies in blood and liquor was negative. There was no sign of immunological disorder.

Auditory Threshold↗