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J Strutz

Publications and source records attributed to J Strutz.

At least 19 recordsLinked to original sources
PubMed1996

[Continuous proliferation of supporting cells and indications for hair cell differentiation in the inner ear of adult song birds with genetic cochlear hearing loss].

Our previous investigations demonstrated that the Belgian Waterslagers (BWS) canary (Serinus canarius) was affected by an inherited sensorineural hearing loss. Compared to normal canaries of others strains, hair cell numbers in these birds were reduced on average by 30%. Since other birds are able to replace similar hair cell numbers after cochlear trauma, we investigated if BWS have the potential for supporting cell proliferation with subsequent hair cell differentiation or if they lack the repair mechanisms known to operate in other birds. In the present study the S-phase marker bromodeoxyuridine (BrdU) was used to demonstrate DNA synthesis and thus cell proliferation. We found on average six labelled nuclei per basilar papilla in BWS. This number of proliferating cells was in accordance with previous estimates of newly generated hair cells as based on the frequency of immature-appearing hair cells observed by scanning electron microscopy. We conclude that the division of supporting cells in BWS precedes the differentiation of hair cells. In contrast to BWS we found on average only one supporting cell division per day in normal canaries of other strains. However, this supporting cell proliferation in normal birds is probably not related to a loss of hair cells and does not lead to the differentiation of new hair cells. Our data indicate that differentiation of hair cells after supporting cell division occurs only if the rate of supporting cell proliferation is increased above the normal low level (probably by the loss of hair cells). Since BWS do not repair their basilar papilla despite a 30% hair cell loss (as compared to normal canaries) although they continuously produce new hair cells, we suggest that the regulation of the regeneration process is abnormal.

Animals↗
PubMed1995

Sound induced expression of c-Fos in GABA positive neurones of the gerbil cochlear nucleus.

To characterize c-Fos-expressing neurones in more detail, a double labelling technique was developed to simultaneously demonstrate the presence of GABA-like and c-Fos-like immunoreactivity in cryostat sections of the gerbil cochlear nucleus. The animals were exposed to a wide-band noise stimulus for the induction of c-Fos expression. The distribution of c-Fos-positive cells and GABA-positive somata was consistent with previous reports. Our double labelling approach revealed the presence of GABA-positive cells that showed c-Fos expression after noise stimulation. One interpretation of this finding is that a prolonged acoustic exposure induces long term changes in inhibitory interneurones to adjust the output of the cochlear nucleus.

Acoustic Stimulation↗
PubMed1995

Blood group phenotype determines lectin-mediated adhesion of Pseudomonas aeruginosa to human outer ear canal epithelium.

Pseudomonas aeruginosa is the most frequent bacterial pathogen causing acute diffuse otitis externa. In a recent prospective phase II study we demonstrated that lectin-mediated bacterial adhesion can be blocked by receptor-analogue carbohydrates in patients suffering from Pseudomonas aeruginosa-induced acute otitis externa. In this investigation, human ABO blood group antigens were analysed on outer ear canal epithelial cells with standard routine histological procedures by monoclonal antibodies for the blood groups A and B, and with Ulex europaeus I lectin for the blood group O, respectively. In all cases (n = 20) the blood groups could be shown immunohistologically. P. aeruginosa-specific adhesion and inhibition assays were performed in the presence of N-acetylgalactosamine (GalNAc), N-acetylglucosamine (GlcNAc), D-mannose and A-like substance. Outer ear canal tissue sections were incubated with P. aeruginosa (strain PA 60), presenting lectin-specificity for GalNAc. Sections from patients presenting with blood group A were closely settled with bacteria in the presence of non-specific GlcNAc, D-mannose and PBS however, GalNAc and A-like substance inhibited the microbial adhesion. Amongst others, P. aeruginosa present adhesion molecules (lectins) with specificity for GalNAc. Thus, the correlation between blood group A phenotype and P. aeruginosa-induced acute diffuse otitis externa was investigated. Statistical evaluation proved a highly significant association. These data support the hypothesis that P. aeruginosa lectins with GalNAc specificity apparently adhere to GalNAc moieties, representing the terminal blood group A-determinant and further indicate that patients presenting with blood group A may have a genetic disposition for this form of otitis externa.

ABO Blood-Group System↗
PubMed1995

[Differential diagnosis of hematotympanum in forensic autopsy].

In a living patient, a hemotympanum can be a sign of a temporal bone fracture. Postmortem endoscopy in forensic autopsy cases also revealed hemotympanum findings without any fracture. Thoracic compression or cranio-facial congestion were probably the pathogenetic mechanism in some of the cases. An engorgement of the internal and external jugular veins was found in all cases. Due to increased intravenous and intraarterial pressure, capillary hemorrhages were revealed in endoscopy and histological sections.

Abdominal Injuries↗
PubMed1995

[Indications of continuous hair cell regeneration in a song bird with genetically-induced cochlear hearing loss].

In recent years evidence has accumulated that birds in contrast to mammals have a great capacity to replace lost hair cells after cochlear trauma. Despite this capacity for cochlear repair, a hereditary hearing deficit for frequencies above 2 kHz has been described in a peculiar strain of canaries (Belgian Water-slagers). Because previous thresholds were determined by psychophysical methods, the origin of the hearing loss could not be identified. In order to determine if this loss originated in the cochlea and if these birds lack the potential for hair cell regeneration, we carried out physiological and morphological analyses of the hearing organ. Our results showed that most of the hair cells displayed severe pathologies. Also, found were small, microvilli-covered cells that resembled forms described during normal hair cell development. Small microvilli-covered cells with small sterovillar bundles have been described as regenerating hair cells in other birds after severe cochlear insults. These observations indicate that adult Belgian Waterslager canaries continuously produce new cochlear hair cells. They do not, however, succeed in reforming a normal basilar papilla. We believe that these birds are a promising model for future studies of cochlear hair cell repair mechanisms.

Animals↗
PubMed1993

[Topical anesthesia of the tympanic membrane and tubal function--is there a correlation?].

The influence of topical anaesthesia of the tympanic membrane on Eustachian tube function was investigated using the pressure chamber impedance method, thus obtaining quantitative data. Anaesthesia was performed by application to the tympanic membrane of small cotton balls containing lidocaine and dimethylsulfoxide. We did not observe significant alterations of tubal parameters after unilateral or bilateral anaesthesia. Our observations are in contrast to investigations published by Nagai. We suppose that differences in methods of topical anaesthesia are responsible for this discrepancy. Our technique of topical anaesthesia of the tympanic membrane excludes any effect on the Eustachian tube, thereby avoiding negative consequences of middle ear pressure on wound healing.

Anesthesia, Local↗
PubMed1993

[Otorhinolaryngologic aspects of diving sports].

ENT disorders are the most common of all medical problems of diving. This review summarizes the specific conditions and ENT diseases in Scuba diving. During compression failure to equalize the pressure of air-filled cavities surrounded by bone deprives the middle ear or sinuses of aeration. Middle ear barotrauma is the most common barotrauma encountered in divers while sinus barotrauma and especially inner ear barotrauma (with rupture of the round or oval window) are less common. Decompression sickness in primarily the result of inert gas bubbles; deafness and vertigo may result if the inner ear is involved. The ENT examination necessary for assessment of diving fitness focuses on the middle and inner ear as well as the nose, sinuses and larynx. A list of ENT contra-indications is presented that mandate temporary or permanent disqualification from diving.

Barotrauma↗
PubMed1993

[3D endoscopy].

With the aid of a 6 mm 0 degree stereo-endoscope supplied with a 100 Hz monitor and high-speed liquid crystal shutter, three-dimensional endoscopy of the upper airway was realized for the first time. The equipment used is based on alternating sequential projections of left and right eye images on a single tv screen. Two high-speed liquid crystal stereo switches (LCSS) are integrated in glasses and a rapid switching time of 100 microseconds is used. In a comparative study this innovative endoscopic technique was tested for its practicability in sinus surgery and endoscopy of the upper airway. With this equipment an excellent view was obtained of the pharynx, larynx and trachea. For sinus surgery, however, a stereoendoscope with smaller dimensions has to be developed.

Computer Graphics↗
PubMed1992

[Perioperative single dose prevention with cephalosporins in the ENT area. A prospective randomized study].

Perioperative systemic antibiotic cover is usually recommended in major head and neck surgery with the aim of preventing postoperative wound infection. The surgeon must administer the drug most suitable for the particular operation and patient at an adequate dosage and over an adequate period. On the other hand, he has an obligation to minimize costs and find ways of avoiding the development of bacterial resistance to the antibiotic. This means that prophylactic antibiotics may not have too broad an antibacterial spectrum and may only be used over the short term. In an attempt to improve antibiotic prophylactic in head and neck surgery, we tested the effectiveness of a perioperative single-dose antibiotic cover with cefuroxim (Zinacef) in patients undergoing parotidectomy, sinus surgery or neck dissection with no transcutaneous exploration of the pharynx. This single-shot prophylaxis was compared with a three-shot, 24-hour regimen using the same antibiotic. The two regimens were equally effective in preventing wound infection and no case of infection was observed among the 106 patients involved. Preoperative concentrations of cefuroxim were measured in serum and tissue, and the large majority of specimens showed effective concentrations against the typical wound infection bacteria. In conclusion, a perioperative single-dose administration of cefuroxim proved to be suitable prophylaxis against postoperative wound infection in head and neck surgery.

Cefuroxime↗
PubMed1992

[Postmortem endoscopic diagnosis].

The use of endoscopical methods augments the macroscopical diagnosis in autopsies. Cavities and sinuses which are hardly accessible may be inspected and photographically documented as well without damage of the anatomical context. In terms of forensic autopsies the endoscopical technique is mostly recommended for the inspection of the fundus of the eye, the external auditory meatus up to the tympanic membrane, the naso- and laryngopharynx. Pathological and traumatical changes can be valued at once in situ. Forensic evidence of postmortal endoscopical findings is exemplified.

Adolescent↗
PubMed1991

[Non-neoplastic central hearing loss--a review].

Acquired central auditory disorders not due to a tumour are unusual. The well-known conditions such as hypoxic encephalopathy, erythroblastosis, bacterial meningitis and trauma are reviewed. Recent experimental and clinical studies contribute to progress in the understanding of the pathogenesis and etiology of these conditions. The pattern of presbyacusis and cortical deafness is discussed also. AIDS must be considered as a new cause of acquired central auditory dysfunction.

AIDS Dementia Complex↗
PubMed1990

Uncontrollable epistaxis. Angiographic localization and embolization.

The method of choice for uncontrollable epistaxis that is refractory to anterior and posterior nasal packing is controversial. In a retrospective study, the therapeutic results in 42 patients with uncontrollable epistaxis were reviewed, with special consideration of 11 cases in which the patients received angiography and embolization of branches of the internal maxillary artery. Out of this collective, only one patient received surgery, ie, transantral internal maxillary artery ligation. The results of primary embolization demonstrated the effectiveness and illustrated the potential role of embolizing procedures in uncontrollable epistaxis.

Adult↗
PubMed1989

[Duplication of the auditory canal. A vestige of the 1st branchial cleft].

Anomalies of the first branchial cleft appear as duplicated auditory canals; they are rare clinical entities. Patients will present with a history of recurrent fistulas of the neck or parotid gland close to the angle of the mandible. There are two distinct malformations associated with the first cleft: A simple sinus which is lined with squamous epithelium and runs parallel to the auditory canal (Type I); the Type II anomaly, on the other hand, has a close, though variable relationship to the facial nerve and contains cartilage, a mesodermal derivate, within the wall. Embryologically it appears that the point of time at which the disorder developed dictates whether the malformation is of Type I or II. The authors present six cases of first branchial cleft anomalies, two patients with Type I and four with Type II lesions. The sex distribution was striking: all the patients were female. In case of a Type II defect, three variations of the facial nerve with split main trunks were found. Recurrent operations and infections lead to scar tissue and subsequent surgery is more difficult, with serious hazard to the facial nerve. Where positive identification of the facial nerve is a major problem it is advisable to identify the nerve in the mastoid cavity and trace it to the stylomastoid foramen and parotid gland.

Adolescent↗
PubMed1988

The motor innervation of the soft palate. An anatomical study in guinea pigs and monkeys.

In an effort to gain a more precise understanding of the motor innervation of the soft palate, a neuroanatomical tracer (horseradish peroxidase) was injected into the vela of nine guinea pigs and four monkeys. After 48 h the animals were sacrificed and frozen frontal sections were appropriately reacted with tetramethylbenzidine and counterstained with neutral red, and then evaluated by means of light microscopy. In all specimens retrogradely labeled neurons appeared in the brain stem. The distribution patterns of these labeled cells were to a large degree comparable in both the guinea pigs and the monkeys. The complex motor innervation of the soft palate was found to involve at least five different centers, with the strongest staining seen in the nucleus ambiguus and the motor nucleus of the trigeminal nerve. Additional cells of origin were discernible in the retrofacial nucleus. Facial neurons, however, were labeled only occasionally. Findings also showed that a previously undescribed component from the hypoglossal nerve appears to be essential for lateral soft palate movement in both animal models.

Animals↗