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Biomedical subjects

J Strutz

Publications and source records attributed to J Strutz.

At least 37 records · Page 2Linked to original sources
PubMed1988

The motor innervation of the tympanic muscles in the guinea pig.

The number and the location of the motor neurons innervating the stapedius or tensor tympani muscles in the guinea pig were identified by retrograde axonal transport of the tracer horseradish peroxidase. Tracer injections were made either into the stapedius or tensor tympani muscle and effected the retrograde labeling of neurons in the ipsilateral brain stem. These findings showed that the stapedius motor neurons lie outside the traditionally recognized facial nucleus and are present in two cell columns: ventromedial and dorsomedial to the facial nucleus. These labeled neurons are dissimilar to cells within the facial nucleus, i.e. they are smaller and more fusiform in shape. The tensor tympani motor neurons were found outside the trigeminal motor nucleus. At a rostral level they were located in a region ventral and ventrolateral to the latter nucleus. These labeled neurons were smaller than the trigeminal motor neurons and polygonal in shape. In the animals studied there were about six times more tensor tympani motor neurons than stapedius motor neurons.

Animals↗
PubMed1988

Effects of topical anesthetics on tympanic membrane structure.

Topical application of a local anesthetic agent can induce adequate insensibility to pain, and therefore can avoid the use of general anesthesia or invasive infiltration techniques for myringotomy or the insertion of a tympanostomy tube. A comparative study was conducted on a guinea pig animal model to determine the effects of three agents on the structure of the tympanic membrane: 5% tetracaine base dissolved in dimethylsulfoxide (DMSO), pure DMSO, and Bonain's solution. Survival times ranged from 1 day to 3 months. Following removal from the animals, membranes were embedded in Spurr and cut in semithin sections. Signs of mild or severe external otitis were frequent; to avoid non-specific results, infected specimens were not evaluated. Bonain's solution caused loss of the epidermis and mucosal epithelium within 1 day of treatment. The connective tissue layers of the drum were severely hyperplastic after a survival time of 1 month. Tetracaine base in DMSO caused a loss of epithelium and mucosal cells in 3 days. Regeneration started within 7 days and a restitution to integrity was seen after 3 months in drums treated with tetracaine base or DMSO alone.

Administration, Topical↗
PubMed1988

[Otologic aspects of diving].

Ear diseases are the most common of all occupational diseases of diving. Otitis externa is the most frequent and troublesome infection in divers especially when the environment is humid. During compression, failure to equalize the pressure of the air-filled cavities surrounded by bone (middle ear, sinus) deprives the middle ear (or sinus) of aeration. Middle ear barotrauma is the most common barotrauma encountered in divers while external ear barotrauma (reversed ear) and inner ear barotrauma (with rupture of the round or oval window) are less common. Decompression sickness (Caisson disease) is primarily the result of inert gas bubbles; deafness and vertigo may result if the inner ear is involved. The most dramatic cause of disorientation under water is that due to vertigo. This vertigo is commonly a transient effect due to unequal caloric stimulation of the two labyrinths. The physical examination of the ear and nose necessary for assessment of diving fitness are discussed. A list of ENT contra-indications is presented which mandate temporary or permanent disqualification from diving.

Barotrauma↗
PubMed1988

[Implantation of 125 iodine seeds in the dog vocal cord. An experimental morphologic study].

Following the first positive therapeutic results of T1a vocal chord cancer with 125iodine seeds in man (brachytherapy), we were concerned with the effects of this low-energy photon source on healthy laryngeal tissue. In the larynx, changes in the area of the vocal chord and the cartilaginous laryngeal structures were investigated in particular. These experimental studies were performed on the larynx of the dog. Through direct laryngoscopy, two 125iodine seeds were implanted in the anterior third of each vocal chord in 8 dogs; the resulting prick canals were sealed with fibrin glue. During survival the correct position of the seeds was radiologically monitored. After survival periods of 1, 3, 6, and 12 months the larynges were fixed by perfusion, removed, imbedded in paraplast, and stained with H. E., Azan, and E. v. G. After this protracted irradiation with 125iodine seeds only slight and for the most part reversible pathological changes had occurred. One month after implantation, only a perivascular infection was found in the vocal chord. After three months an inhibition of the fibrin organization around the seeds was observed as well as a localized dyschylia with broadening of the gland ducts. Additionally, a circumscribed dysplasia of the squamous epithelium, swelling of the capillary endothelium, atrophy of muscular fibres around the seeds, and telangiectasia of blood vessels were discernable. 6 and 12 months after implantation, only the muscular atrophy and the telangiectasia of the blood vessels remained detectable, in addition to a reduced inhibition of the fibrin organisation by connective tissue.

Animals↗
PubMed1988

[A lidocaine base for surface anesthesia of the tympanic membrane].

An anatomical study was conducted to determine the effects of 10% lidocain base (dissolved in DMSO) on the structure of the tympanic membrane. Survival times ranged from 1 day to 3 months. Membranes were embedded in plastic and cut in semithin sections. Within 1 and 3 days mild swelling of the epithelium was seen; 1 month after treatment the connective tissue layers of the lamina propria were severely hyperplastic. 2 months after lidocain-Base application additional collagen fibres, loosely packed and less regularly, appeared in the submucosal connective tissue layer. However, normal appearance of the drums was noticeable after 3 months survival.

Anesthesia, Local↗
PubMed1988

[A rare nasopharyngeal tumor: Hodgkin's disease].

Primary cases of Hodgkin's disease in the nasopharynx are extremely rare. The authors report on two such cases: A 27 year old male had a large tumour, lined with a smooth mucous membrane, in the nasopharynx. The results of examinations of the neck, thorax, and abdomen were normal. The tumour was removed through the palate. Histological findings confirmed the diagnosis of lymphocyte-prominent Hodgkin's disease (subtype paragranuloma). 11 years ago a nasopharynx tumour was removed by adenotomy from a 57 year old female. A diffuse hyperplasia of the lymphatic tissue was diagnosed at the time. Recently cervical lymph nodes appeared, and a second tumorous lesion was discovered in the nasopharynx. Histological examination of the tumour and cervical lymph node indicated lymphocyte-prominent Hodgkin's disease (subtype paragranuloma). On re-examining histological sections from the tumour removed 11 years ago, the authors again saw the types of change indicative of Hodgkin's disease. The probable course and outcome of lymphocyte-prominent Hodgkin's disease of the nasopharynx, especially of the paragranuloma subtype of the disease, are discussed. Treatment of both patients included adjuvant extended-field radiotherapy.

Adult↗
PubMed1987

[Innervation of the stapedius muscle. A study using horseradish peroxidase in the guinea pig].

The numbers and locations of motoneurons to the stapedius muscle were determined by retrograde axonal transport of horseradish peroxidase (HRP) in the guinea pig. With the aid of a drill the bulla was opened and the stapedius muscle exposed. HRP solution (0.2-0.3 microliter) was injected into the muscle. Following a survival time of 1-2 days the animals were perfused with a fixative and the brains were removed. Frozen sections were reacted fro the demonstration of HRP using tetramethylbenzidine as chromagen. All labelled neurons were observed not within the traditionally recognised facial nucleus but ventral and medial to the latter. All parent cells (up to 64) lay ipsilateral to the injection. These neurons were remarkably smaller in shape than the neurons in the facial nucleus.

Afferent Pathways↗
PubMed1987

[Anatomy of the central auditory pathway. Demonstration with horseradish peroxidase in the guinea pig].

The neurones of the afferent and efferent auditory pathways were labelled by axonally transported horseradish peroxidase. The first neurone of the ascending system is the acoustic nerve with the spiral ganglion. These fibres terminate mainly in the ventral cochlear nucleus (VCN). The neurones of the latter chiefly run to the contralateral superior olivary complex (SOC), whereas the neurones of the dorsal cochlear nucleus (DCN) terminate mainly in the central nucleus of the contralateral inferior colliculus (IC). The nerve cells of the superior olivary complex and nuclei of the lateral lemniscus (DLL, VLL) project to the IC. The IC neurones run mainly uncrossed to the medial geniculate body (MGB), i.e. the neurones of the central nucleus of the inferior colliculus terminate in the ventral nucleus of the medial geniculate body. This latter nucleus projects to the primary region A I of the auditory cortex, whereas the neurones in the pericentral medial geniculate body terminate in the associated auditory regions A II, EP and SF. The auditory areas of both hemispheres is well interconnected by commissural fibres. In addition to this ascending pathway there is a descending system. The parent cells correspond to pyramidal neurones in layer V in the auditory cortex. These neurones terminate in the medial geniculate body and in the pericentral nuclei of the inferior colliculus. From this, efferent neurones project to the DCN and SOC. The neurones of the olivocochlear bundles originate in the SOC; these bundles terminate predominantly on the surface of the outer hair cells in the organ of Corti.

Animals↗
PubMed1987

[Middle ear implants (Tübingen type) of Al2O3 ceramics. Follow-up to 6 years after surgery].

Since 1980 we have been using Al2O3 ceramic implants in some reconstructions of the ossicular chain. We began interposing a small autologous cartilage perichondrium disk between implants of this type and the ear-drum after having observed the first cases of imminent extrusion and of extrusion. Thus about half the implants in our first follow-up study. in 1984, were shielded by a cartilage disk; in 1984 91 patients (108 ears) were examined. 64 of the same patients (66 ears) consented to be re-examined in a second follow-up study in 1986. Of the 66 Al2O3 ceramic implants in the smaller sampling 43 had a cartilage overlay, and 23 did not. The implants without a cartilage overlay had been in situ for 3 to 6 years, and on average for 59 months; those with a cartilage overlay had been in situ for 3 to 6 years, and on average for 59 months; those with a cartilage overlay had been in situ for 2 to 5 years, and on average for 39 months. Both studies show the feasibility of markedly reducing the risk of imminent extrusions and extrusions, which occur when the cavum tympanum is poorly ventilated and the ear-drum retracts. The extrusion rates for Al2O3 middle-ear implants with and without a cartilage overlay were 5% and 16% respectively from 1980 to 1986. The great majority of ears examined showed a residual air-bone-gap of 0 to 20 dB in the frequency range between 0.5 and 2 kHz. Our audiometric results were essentially the same in 1984 and 1986.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum↗
PubMed1986

[Epidemiology of benign paroxysmal positional vertigo].

Every ninth patient with a previous history of vertigo at the ENT Hospital of the University of Freiburg suffers from BPPV. The incidence, some important pathogenetic factors and the clinical picture of BPPV are discussed. In young men posttraumatic aetiology dominates, whereas idiopathic BPPV prevails in perimenopausal women. The affected ear tends to be hard of hearing in the high frequencies and is sometimes hypoexcitable by caloric stimulation. The diagnosis is best made by personal examination with Frenzel's glasses in darkness. Electronystagmography, brainstem evoked response audiometry, and CT scanning are of no particular value in confirming the diagnosis of BPPV.

Adult↗
PubMed1986

[Polyglactin 910 (Vicryl) net in myringoplasty. An animal experiment and clinical study].

According to studies by Dociu (1978), the resorption of Vicryl sutures causes only a slight foreign-body reaction in the back musculature of rats. Similarly, in experimental studies by Bowald et al. (1978) Vicryl mesh is reported to be an excellent material for use in the reconstruction of arteries; the chief virtue attributed to it is that it promotes cell proliferation during the healing process, and so promotes the growth of new arterial walls. Stimulated by Dociu's and Bowald's favourable results, we decided to study the influence of an impregnated, and hence stiffer, Vicryl mesh on the outcome of myringoplasties. Myringoplasties were performed on both ears of 15 cats. One ear drum of each cat was reconstructed with fascia and Vicryl mesh, the other (= control) ear drum with fascia only. In addition, myringoplasties with autologous fascia and Vicryl mesh were performed on 18 patients. The absorption of Vicryl mesh results in a temporary but pronounced foreign-body reaction. In consequence, the tympanic membrane temporarily thickens and is thoroughly vasculated. According to our findings Vicryl mesh does not promote the growth of a new tympanic membrane. In our patients we noticed pulpy swelling of the fascia after myringoplastic surgery with fascia and Vicryl mesh. From the above we conclude that Vicryl mesh is not suitable for splintage in myringoplastic surgery.

Animals↗
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↗