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Biomedical subjects

J Strutz

Publications and source records attributed to J Strutz.

At least 55 records · Page 3Linked to original sources
PubMed1984

Efferent acoustic neurons within the lateral superior olivary nucleus of the guinea pig.

The cells of origin of the olivocochlear bundles in the guinea pig were labeled by retrograde axonal transport with either the fluorescent dye 'Fast Blue' or horseradish peroxidase (HRP). Labeled cells were found bilaterally in the superior olivary complex, as described previously. Moreover, an extremely large population of labeled cells occurred within the cell mass of the lateral superior olivary nucleus (LSO) ipsilaterally to the injection site. Preliminary electron microscopical observations confirmed that the labeled LSO cells were distinctly smaller than the unlabeled LSO cells. The labeled cells contained a large nucleus that exhibited extensive invaginations.

Animals↗
PubMed1983

[Obliteration of the mastoid cavity with porous tricalcium phosphate ceramic. Results 12 and 18 months after ceramic implantation in the hypotympanon of the pig].

The paper reports on the obliteration of mastoid cavities with resorbable tricalcium phosphate ceramic. As a model, we chose the pneumatic air cell system of the pig's hypotympanon, which resembles the human mastoid. At the time of surgery, the specimens were 10-12 weeks old. In a first group the cells of the hypotympanon were totally removed and the operation cavity was obliterated with adjacent layers of porous tricalcium phosphate ceramic. In a second group of specimens the air cell system was partly removed, leaving the apical part of the hypotympanon intact; the operation cavity was obliterated again with porous tricalcium phosphate ceramic. After 12 and 18 months survival the hypotympanons were removed and prepared for histological investigations. Those ceramic plates, lying close to the bony shell were strongly resolved and replaced by new bone. Other ceramic plates, however, especially those in the center of the implant, showed few signs of resorption and bony remodelling. Inside the ceramic implant there was hardly connective tissue. The space between the still unsolved ceramic plates was filled up with new bony tissue. This bone was partly structured and adjoined directly to the ceramic. The ceramic was integrated into the new bony tissue without any sign of an inflammation.

Animals↗
PubMed1982

The origin of efferent fibers to the inner ear in a turtle (Terrapene ornata). A horseradish peroxidase study.

The origin of efferent acoustic and vestibular fibers was determined in the turtle Terrapene ornata. After injection of an aqueous solution of horseradish peroxidase (HRP) into either the cochlear duct or into the ampullae of the horizontal and anterior semicircular canals, neurons in the medullary reticular formation were labeled by the reaction production of retrogradely transported HRP. These neurons were located bilaterally in the medial reticular nucleus. The majority were found ipsilateral to the injection site. There was no demonstrable difference in size, shape, and labeling pattern between efferent acoustic and efferent vestibular neurons. The crossed component component of efferent acoustic fibers, however, was rather sparsely developed.

Animals↗
PubMed1982

The origin of efferent labyrinthine fibres: a comparative study in vertebrates.

Parent cells of efferent acoustic and efferent vestibular fibers were determined anatomically in all classes of vertebrates by use of retrograde axonal transport of horseradish peroxidase. These neurons were found in the brainstem, in particular in the reticular formation. In the goldfish, efferent labyrinthine neurons could be demonstrated in a medial position (lateral to the fasciculus longitudinalis medialis). In the frog, efferent neurons appeared more lateral, dorsomedial to the facial motor nucleus. In reptiles and birds, efferent acoustic neurons separate from efferent vestibular neurons. In mammals, efferent vestibular neurons are located more dorsally, lateral to the genu of the facial nerve. Efferent acoustic neurons take their origin from the superior olivary complex.

Alligators and Crocodiles↗
PubMed1982

Location of efferent neurons to the labyrinth of the green tree frog (Hyla cinerea). A horseradish peroxidase study.

The origin of centrifugal fibers to the labyrinth was determined by application of horseradish peroxidase to the severed octavus nerve of the green tree frog (Hyla cinerea). Labeled neurons were found exclusively in the nucleus reticularis medius of the reticular formation ipsilateral to the injection site. In particular, no retrogradely labeled neurons were found in the octavus nuclei.

Animals↗
PubMed1982

[Are porous tricalcium phosphate ceramics suited for the replacement of bony walls in ear surgery? An animal experiment study of the hypotympanum of the domestic swine].

The purpose of this study was to examine the possibility of a partially or totally posterior canal and lateral attic wall reconstruction with a more stable and therefore less porous tricalcium phosphate ceramic plate (S8). The hypotympanon of 4 pigs was drilled out, leaving the bony shell intact. In the middle part of this cavity a 2 mm thick S8-ceramic plate was placed horizontally. The hypotympanon of further 11 pigs was drilled out and obliterated with a more porous tricalcium phosphate ceramic (S5). Additionally, a single S8 ceramic plate served as a wall to the cavum tympani. 1 to 18 months after operation the pigs were sacrificed; sections of the hypotympanon were investigated with light microscopy. After few weeks, the S8-ceramic plate was covered by granulation tissue and epithelium on the tympanic side. After three months newly formed bony tissue could be observed between the peripheral parts of the S8-ceramic plate and the tympanic epithelium. After six months both sides of the S8-ceramic plate were completely covered by new bone; moreover this bone is covered by the mucosa on the tympanic side. At this time the S8-ceramic plate has a tight bony contact to the shell of the hypotympanon and bone growth can be observed in the macropores of this plate. The bony layer on the tympanic side of the S8-ceramic plate remained slim, there was no exophytic growth after 12 months. After 18 months the S8-ceramic plate shows distinct signs of resorption and bony replacement. However, in comparison to the S5-ceramic this occurs slower and later.

Animals↗
PubMed1981

The origin of centrifugal fibers to the inner ear in Caiman crocodilus. A horseradish peroxidase study.

The origin of acoustic and vestibular efferent fibers was investigated in Caiman crocodilus. After injection of horseradish peroxidase (HRP) into the cochlear duct or into the ampullae of the horizontal and anterior semi-circular canals, cells in the medulla oblongata exhibited retrogradely transported HRP reaction product. Efferent vestibular fibers were found in the medial reticular nucleus, at the level of the oliva superior. There were more labeled neurons ipsilateral to the injection site. Efferent acoustic neurons were found close to or inside the rostroventral division of the oliva superior. They spread out into the medial reticular nucleus bilaterally, More labeled efferent acoustic neurons occurred contralateral to the injection site.

Alligators and Crocodiles↗
PubMed1981

Origin of centrifugal fibers to the labyrinth in the frog (Rana esculenta). A study with the fluorescent retrograde neuronal tracer 'Fast blue'.

After injecting a solution of a fluorescent retrograde neuronal tracer (Fast blue, Diamidino compound 253/50) into the perilymphatic space of the frog labyrinth (Rana esculenta), labeled cells were found in the ventral and dorsal nuclei of the VIIIth nerve and in the nucleus reticularis medius. We consider these labeled cells to be the origin of the efferent innervation of the frog labyrinth. No evidence was found for the existence of a direct cerebello-labyrinthine connection.

Afferent Pathways↗
PubMed1981

[The origin of efferent fibers to the inner ear on reptiles. A HRP study in Caiman crocodilus (author's transl)].

The origin of efferent fibers to the inner ear was studied in Caiman crocodilus. After injection of horseradish peroxidase into the basilar papilla or into the ampullae of the horizontal and anterior semicircular canals, neurons labeled by the granular reaction product of retrogradely transported HRP were found in the medulla oblongata bilaterally. Parent cells of the efferent cochlear bundle were found in the medial reticular nucleus and in the rostroventral division of the superior olive bilaterally. Efferent vestibular neurons were found in the medial reticular nucleus bilaterally with more neurons ipsilateral to the injection site.

Alligators and Crocodiles↗
PubMed1981

[The auditory pathway in guinea pigs. A [14C]2-deoxyglucose study (author's transl)].

The auditory pathway of guinea pigs was labeled with [14C]-deoxyglucose after mon- or binaural stimulation with farfield white noise in a sound-proof chamber. In the autoradiographs, all auditory nuclei were labeled. The highest metabolic effects were seen in the dorsal cochlear nucleus, the lateral superior olivary nucleus, and in the inferior colliculus. No selective labeling was observed in the auditory cortex. Monaural stimulation depressed the metabolic activity contralaterally in the ventral cochlear nucleus and ipsilaterally in the medial nucleus of the trapezoid body, the dorsomedial periolivary nucleus, and in the inferior colliculus.

Acoustic Stimulation↗
PubMed1981

[Obliteration of the mastoid air cell system with porous tricalcium phosphate ceramic. An animal experiment of the bulla tympanica of the pig (author's transl)].

The paper reports on an animal experiment on the obliteration of mastoid cavities with tricalcium phosphate ceramic. The pneumatic air cell system of the bulla tympanica of pigs of 11-12 weeks of age was totally removed in one group of animals and partially removed in the second group. In this second group, apical part of the bulla was left intact. The operation cavity was then obliterated with adjacent layers of porous tricalcium phosphate ceramic. Histological sections wee evaluated for both groups of animals after survival time of 1, 3 and 6 months. Initially, an ingrowth of granulated tissue between the ceramic layers and into the porous surface can be observed. This dissolves the ceramic material, which is substituted by bony tissue. Pneumatic cells in the apical part of the bulla, which were left intact in the second group of animals, do not obliterate after the air supply has been cut off by sealing the basal part. Cystic cavities remain which contain a serous exudate. After 6 months, the mucous membrane of such cells shows signs of "sclerosis". Formation of spongy bony tissue with marrow spaces can be seen in most of the apical areas of the growing bulla. There is no formation of air-containing cells. It appears from our preliminary results obtained from animal experiments that porous tricalcium phosphate ceramic may be a suitable material for the obliteration of mastoid cavities.

Animals↗
PubMed1980

Origin of efferent fibers of the vestibular apparatus in goldfish. A horseradish peroxidase study.

After injecting a horseradish peroxidase (HRP) solution into the vestibular apparatus in goldfish (Carassius auratus), cells in the medulla oblongata exhibited retrogradely transported HRP reaction product. These labeled cells were confined to 3 nuclei, i.e. the nucleus motorius tegmenti of Bartelmez (with the most prominent labeled cell groups), the ventral vestibular nucleus (Dieter's nucleus) and the medial vestibular nucleus. We consider these labeled cells to be the origin of the efferent innervation to the vestibular apparatus in goldfish. Neurons providing efferent innervation to the sensory periphery in the nucleus motorius tegmenti have, as yet, not been described.

Animals↗
PubMed1980

[The origin of the afferent innervation to the inferior colliculus in guinea pig. A horseradish peroxidase study (author's transl)].

The innervation of the inferior colliculus in guinea pig was studied using the method of retrograde axonal transport of horseradish peroxidase (HRP). Following injections of HRP into the central nucleus of the inferior colliculus (IC) HRP labeled cells were found in all auditory nuclei as well as in the temporal cortex. Virtually all neurons of the ventral nucleus of the lateral lemniscus and the medial superior olivary nucleus ipsilateral to the injection side appear to project to the IC. A large number of labeled cells exhibited in the dorsal nucleus of the lateral lemniscus and in the ventral and dorsal cochlear nuclei contralaterally. The lateral superior olivary nucleus was evenly labeled bilaterally while among the periolivary nuclei the dorsomedial periolivary nucleus was heavily labeled ipsilateral to the injection side. Furthermore, labeled neurons occurred in the contralateral IC and in the ventral part of the medial geniculate body on both sides. The pyramidal cells of layer V of the temporal cortex were heavily labeled ipsilaterally.

Animals↗
PubMed1980

[Advantages and risks in metrizamide-meatocisternography (author's transl)].

Meatocisternography with iodinated lipoid contrast media has been proven one of the most reliable diagnostic methods in the evaluation of small cerebellopontine angle tumors. Use of this kind of positive contrast media, however, has certain disadvantages. Some of these disadvantages can be avoided using water soluble contrast medium. Possible adverse reactions demand premedication and clinical observation over a period of 24 hours.

Cerebellopontine Angle↗
PubMedDate not supplied

Correlation of 3D MRI and clinical findings in the patients with sensorineural hearing loss and/or vertigo.

The aim of the study was to correlate clinical and magnetic resonance imaging (MRI) (3D CISS and MP-RANGE) findings in patients with sensorineural hearing loss (SNHL) and/or vertigo. We found a high correlation of MRI and symptoms (17 out of 18 patients, 13 out of 13, respectively) concerning detectability of tumors and acute labyrinthitis. In the case of labyrinthine fibrosis, the correlation between clinical and MRI findings was lower. In conclusion, high-resolution MRI is very suitable in patients with SNHL or vertigo caused by tumors or acute labyrinthitis.

Adolescent↗