Biomedical subjects

M Burian

Publications and source records attributed to M Burian.

At least 37 records · Page 2Linked to original sources

PubMed1999

The blood supply of the sternocleidomastoid muscle and its clinical implications.

BACKGROUND: The knowledge of the exact anatomy of the sternocleidomastoid (SCM) muscle and its nerve and blood supply must be considered a basic prerequisite for its use as a pedicle muscle flap. OBJECTIVE: To give an exact description of the courses and variability of all vessels supplying the SCM muscle. DESIGN: Anatomic analysis of all arteries supplying the SCM muscle. SETTING: The blood supply of the SCM muscle was studied by dissecting bilaterally the anterior regions of the neck of 31 perfusion-fixed human cadavers of both sexes aged 50 to 94 years (mean, 78 years). RESULTS: The blood supply to the SCM muscle can be divided into 3 parts: upper, middle, and lower. The upper third of the SCM muscle was found to be constantly supplied by branches of the occipital artery. According to their courses, these branches are categorized into types 1, 2a, 2b, and 3. The middle third of the SCM muscle receives its blood supply from a branch of the superior thyroid artery (42%), the external carotid artery (23%), or branches of both (27%). In most cases, the lower third of the muscle was supplied by a branch arising from the suprascapular artery (>80%), which has not been described until now. CONCLUSIONS: In contrast to available data, the arterial blood supply of the lower third of the SCM muscle is constantly provided by a branch of the suprascapular artery. Since the SCM muscle flap is used in reconstructive surgery of the neck, the exact knowledge of its blood supply may help to minimize the risk of flap necrosis after surgical procedures.

Aged↗

PubMed1999

[Malignant tumors of the mouth cavity and oropharynx. Stage classification].

Staging of malignant tumours of the oral cavity and the oropharynx not only requires far more than a basic knowledge of anatomy and the usual pathways of spread, but also a broad understanding of the diagnostic benefits of current imaging modalities. As radiology should never try to replace histology, the main aim should be precise prediction of tumour margins and differentiation of tumour from edema and posttherapeutic changes. Only then will imaging studies have a significant clinical impact.

Carcinoma, Squamous Cell↗

PubMed1999

Potential relevance of agmatine as a virulence factor of Helicobacter pylori.

The polyamine agmatine is able to increase gastric acid secretion. Therefore, we investigated whether Helicobacter pylori is able to form and release agmatine in vitro and in the human stomach in vivo, and if so, whether a relationship exists among agmatine concentration in gastric juice, H. pylori infection, and gastroduodenal lesions. Agmatine was determined by means of HPLC. In the supernatant of H. pylori cultures, agmatine concentrations up to 1500 ng/ml (approximately 12 microM) were determined, depending on the number of the bacteria in the individual cultures. Agmatine concentration in gastric juice from H. pylori-positive patients was higher than in that from H. pylori-negative patients. Gastrin in blood was elevated in H. pylori-positive patients compared with H. pylori-negative patients. Agmatine concentration in gastric juice and serum gastrin level appeared to be related. In conclusion, H. pylori is able to form and to release agmatine in vitro and in vivo. This may be assumed to be relevant in vivo, since higher amounts of agmatine are present in gastric juice from H. pylori-positive than from H. pylori-negative patients. Accordingly, agmatine produced by H. pylori may be a virulence factor of this bacterium and may be involved in the pathogenesis of gastroduodenal lesions.

Agmatine↗

PubMed1999

Vascular endothelial growth factor (VEGF) and microvessel density in squamous cell carcinomas of the larynx: an immunohistochemical study.

The distribution of vascular endothelial growth factor (VEGF), one of the most important angiogenic factors, and microvessel density (MVD) were assessed in laryngeal carcinomas by means of immunohistochemistry. Correlation of VEGF with MVD and clinical parameters (T stage, N stage, histological grading, survival, recurrence-free interval) was also examined. VEGF expression was evaluated semi-quantitatively and was observed in varying intensity (i) in tumour cells, (ii) in the stromal department as diffuse, sometimes strong reactivity, especially in close proximity to tumour masses and (iii) in macrophages and endothelial cells. Normal epithelium presented no VEGF reactivity except in the immediate vicinity of tumour transformation. Forty percent of our specimens exhibited substantial VEGF reactivity, whereas 20% showed no staining in tumour cells and stroma. These results could be positively correlated with MVD. Moreover, high-graded carcinomas revealed higher VEGF expression, but there was no association of tumour stage or lymph node status with VEGF or MVD. There was a trend in the survival and recurrence analysis towards a higher risk of disease relapse and shorter survival time for patients with enhanced VEGF expression. Apart from tumour cells, macrophages seem to be a substantial source of VEGF in carcinomas. This observation supports the concept of a pivotal role of these cells in tumour defence--in our case, promoting tumour formation by contributing to neovascularization. VEGF was also found in the connective tissue, where it seems to be bound on collagens and probably builds a reservoir for rapid enzymatic mobilization.

Aged↗

PubMed1999

Angiogenic factors in laryngeal carcinomas: do they have prognostic relevance?

Angiogenesis is a cascade-like mechanism essential for tumour growth and metastasis. Recently developed inhibitors of angiogenesis have already proven their benefit in anticancer treatment. Therefore the existence of angiogenic molecules in individual tumours is of major interest. The factors most frequently contributing to angiogenesis are basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and some matrix metalloproteinases (MMPs). In order to evaluate the prognostic significance of these molecules we investigated the distribution pattern of VEGF, bFGF, MMP-2 and MMP-9 in 41 laryngeal carcinomas using immunohistochemical methods. The results were correlated with clinicopathological parameters, i.e. T and N stage, histological grading, freedom from disease, overall survival and microvessel density (MVD). Only VEGF revealed a correlation with MVD (p = 0.01) and a weak association with histological grading (p = 0.06). Even though there is controversy about published data on the prognostic relevance of angiogenic factors, our results suggest that the factors examined in this study are not suitable for prognosis in larynx cancer patients.

Carcinoma, Squamous Cell↗

PubMed1998

The external branch of the superior laryngeal nerve: its topographical anatomy as related to surgery of the neck.

OBJECTIVE: To determine the possible courses of the external branch of the superior laryngeal nerve (EBSLN) and its relationship to the superior thyroid artery (STA) to improve the chances of identifying and saving the nerve during head and neck surgery. DESIGN: Anatomical analysis of the exact topography of the EBSLN. SUBJECTS: Thirty-one perfusion-fixed human cadavers (ie, 62 preparations) of both sexes ranging in age from 50 to 94 years (mean, 78 years) with neither enlarged thyroid glands nor any other signs of abnormality in this region. RESULTS: Four types of relationship between the EBSLN, the upper pole of the thyroid gland, and the STA were found. In 23 preparations (42%), the EBSLN crossed the STA more than 1 cm above the upper pole of the thyroid gland (type 1). In 15 preparations (30%), the EBSLN crossed the STA less than 1 cm above the upper pole of the thyroid gland (type 2). In 7 preparations (14%), the EBSLN crossed the STA under cover of the upper pole of the thyroid gland (type 3). In 7 preparations (14%), the EBSLN descended dorsal to the artery and only crossed the branches of the STA immediately above the upper pole of the thyroid gland (type 4). CONCLUSION: The description of the variable course of the EBSLN and its categorization may help minimize the risk of iatrogenic lesions of the nerve during surgery.

Aged↗

PubMed1998

Vascular endothelial growth factor is constitutively expressed in normal human salivary glands and is secreted in the saliva of healthy individuals.

The expression of vascular endothelial growth factor (VEGF), a specific mitogen for endothelial cells, was examined in salivary glands and in normal saliva. In normal salivary glands, VEGF mRNA and protein were strongly present in acinar cells, whereas little or no VEGF was found in ductal cells. In chronically inflamed glands, VEGF protein was in addition present in ductal elements and in infiltrating mononuclear cells. No difference of VEGF expression was observed between benign and malignant salivary gland tumours. By ELISA, whole saliva of 24 healthy individuals contained up to 2.5 ng/ml (mean 1.4 ng/ml; SD 0.77 ng/ml) of VEGF, confirming the constitutive secretion of this cytokine by human salivary glands. Western blot analysis of normal saliva under non-reducing conditions detected anti-VEGF reactive protein moieties of approximately 46 kD, corresponding to VEGF secreted by cells in tissue culture. Additional anti-VEGF reactive proteins of approximately 60 and 90 kD were detected in the saliva of some individuals. The presence of considerable quantities of VEGF in normal human saliva suggests an important role for this cytokine in the maintenance of the homeostasis of mucous membranes, with rapid induction of neoangiogenesis by salivary VEGF helping to accelerate wound healing within the oral cavity. Moreover, salivary VEGF may permeabilize intraglandular capillaries and thus participate in the regulation of saliva production itself.

Blotting, Western↗

PubMed1998

Carbocyanine postmortem neuronal tracing. Influence of different parameters on tracing distance and combination with immunocytochemistry.

Carbocyanines (DiI, DiA, DiO) are able to travel along membranes by diffusion and therefore have been used as postmortem neuronal tracers in aldehyde-fixed tissues. Surprisingly, detailed data on the influence of different parameters on tracing distances are still missing. This study was carried out to optimize tracing procedures and to reveal the validity of the combination of postmortem tracing with immunocytochemistry. Carbocyanine crystals were applied to the cervical spinal cord, sciatic nerves, and brachial plexuses of humans and guinea pigs. Incubation in the dark at 37C for 12-15 weeks proved optimal to achieve longest tracing distances (28.9 +/- 2.2 mm) in human and animal tissues. Longer incubation times and incubation temperatures higher than 37C did not result in longer tracing distances. No differences were evident between adult and newborn animals and between central and peripheral nervous system. The diffusion coefficient for DiI was calculated to be 2.5 x 10(-7) cm2 sec-1. After application of DiI to nerves of guinea pig extraocular muscles, DiI-positive afferent perikarya were observed in the anteromedial part of the trigeminal ganglion. These perikarya were identified by calcitonin gene-related peptide immunoreactivity (CGRP-IR). The percentage of CGRP-IR neurons after tracing was concordant with the percentage of CGRP-IR in trigeminal ganglia exclusively processed for CGRP-IR without previous postmortem tracing. These results demonstrate carbocyanines to be specific tracers for exact neuronal mapping studies. (J Histochem Cytochem 46:901-910, 1998)

Aged↗

PubMed1998

Characterization of I2 imidazoline and sigma binding sites in the rat and human stomach.

Radioligand binding experiments were carried out to identify and characterize nonadrenoceptor [3H]idazoxan binding sites and [3H](1, 2-di-(2-tolyl)guanidine) binding sites in the rat and human stomach. Furthermore, we examined two selected aspects of their potential functional significance. Binding of [3H]idazoxan (Kd = 11.1 nM and 12.4 nM, respectively) and [3H]DTG (Kd = 932 nM and 242 nM, respectively) to cell membranes from rat and human stomach was rapid, reversible, specific and saturable. In rat stomach, binding of the radioligands was inhibited by imidazolines and by nonimidazoline sigma-site ligands, respectively, at different rank orders of affinity, which suggests the existence of I2-imidazoline binding sites as well as sigma2-sites. In two functional models, the direct effects of I2-site ligands and sigma2-site ligands on gastric smooth muscle and glands were investigated. (1) Cirazoline, clonidine and 4-chloro-2-(2-imidazolin-2-ylamino)-isoindoline (BDF 6143) failed to contract the longitudinal muscle of the rat stomach fundus; BDF 6143 also failed to induce relaxation of this preparation when it was precontracted with 30 mM KCl. (2) Clonidine, idazoxan, BDF 6143, 1, 2-di-(2-tolyl)guanidine, agmatine and (R)-3-(3-hydroxyphenyl)-N-propylpiperidine up to 100 microM did not induce acid secretion from rabbit isolated gastric glands. Our data provide evidence that the rat stomach is endowed with sigma2 sites and I2 binding sites in addition to the previously identified non-I1/non-I2 [3H]clonidine binding sites. Our experiments also offer basic evidence of the existence of I2 and sigma binding sites in the human stomach. Neither the I2 and [3H]clonidine binding sites nor the sigma sites in rat stomach are directly related to a postsynaptic effect on gastric smooth muscle or to acid release from isolated gastric glands.

Adrenergic alpha-Antagonists↗

PubMed1997

[Inflammations and tumors of the temporal bone].

The term 'inflammation of the middle ear' covers a couple of diseases which range from the acute otitis media to the middle ear cholesteatoma. However, a clear characterization of a certain pathology is essential for any further treatment. Therefore this article presents a short overview about the different types of infections and their clinical manifestation. The tumors of the temporal bone show a great variety in their incidence. Even if tumors like the acoustic neurinoma or the paraganglioma are comparatively common, the chondroblastoma of the temporal bone is absolutely rare. In spite of these differences the individual temporal bone neoplasias are shortly mentioned herein.

Ear Neoplasms↗

PubMed1997

Primary neuroendocrine (merkel cell) carcinoma of the anterior skull base.

A case of a primary neuroendocrine (Merkel cell) carcinoma arising in the anterior skull base involving the dura, both frontal lobes, and the paranasal sinuses is presented. The tumor was completely removed by an enlarged bifrontal transbasal approach. The neuropathological, immunohistological, and electron microscopical investigation revealed all characteristics of a Merkel cell carcinoma, normally presenting as a skin carcinoma of the head and neck. The history, treatment, neuropathology, and possible explanation for this rare manifestation are discussed.

Case Reports↗

PubMed1997

[Late functional outcome after reconstruction of the upper aerodigestive tract with free transplanted microvascular anastomosed jejunum].

Since 1983, 90 autologous jejunal transplantations for reconstruction of the upper digestive tract have been performed in 89 patients (9 females, 80 males, average age 56.3 years). 73 patients were operated primarily, in 16 patients a recurrent tumor had been treated. One patient received a second jejunal graft after necrosis. In these heterogenous patients, the primary tumor was located in the hypopharynx 48 times, in the larynx 21 times, in the oropharynx 19 times and twice in the oral cavity. There was nearly always tumor stage III or IV without distant metastases. Following locoregional tumor resection, speech restoration was achieved 35 times by a siphon-like tube, and the upper digestive tract was reconstructed using a patch 18 times and by a tube 28 times. A combination of tube or patch with a siphon-like tube was employed 9 times. In only two of 16 patients with recurrent tumor, speech reconstruction was performed, in the other 14, the upper digestive tract was reconstructed. In those patients, in whom speech reconstruction (by siphon tube or by combination with tube/patch) was intended, this was achieved in 81.5%. Successful functional reconstruction of the upper digestive tract (by patch, tube, combination) could be achieved in about 60% of these patients.

Adenocarcinoma↗

PubMed1993

Preclinical detection of initial vestibulocochlear abnormalities in a patient with multiple sclerosis.

A 49-year-old woman presented with a third-degree continuous spontaneous nystagmus to the left which was followed by a sudden, almost complete deafness of her left ear. These symptoms were established as the sole initial presenting manifestations of multiple sclerosis (MS). Magnetic resonance imaging demonstrated a lesion within the left eight nerve root-entry zone and multiple small central lesions beneath the lateral ventricles. Pure-tone audiometry returned to normalcy after 2 weeks and speech discrimination was 100% after 10 weeks. Auditory brainstem responses (ABRs) showed abnormal parameters during a 10-month follow-up period after the acute hearing loss. Furthermore, desynchronization in ABR testing could be demonstrated 2 days before onset of hearing loss, which was interpreted as a prodromal ABR sign of the incipient MS attack.

Adult↗

PubMed1992

Specificity of auditory brainstem response audiometry criteria in acoustic neuroma screening as a function of deviations of reference values in patients with cochlear hearing loss.

On the basis of 79 patients with cochlear hearing loss, the statistical distribution of two criteria commonly used in auditory brainstem response audiometry (ABR) was analyzed: the interaural V latency difference (ILD V) and the interaural difference of I-V interpeak interval (ID I-V). The distribution of both criteria was Gaussian. By evaluating their standard deviations the percentages of statistical false-positives were estimated. The estimated results were 24% false-positive findings using the decision criterion ILD V greater than 0.2 ms and 5.4% false-positive findings using ID I-V greater than 0.3 ms. This corresponds closely to the actual false-positive ABR rates obtained in this sample: 21.5% and 6.3%, respectively. In a separate series of 301 unselected cases with asymmetric sensorineural hearing loss, 29 ABRs were suspect for retrocochlear pathology. In 20 patients, ABRs were absent due to severe hearing loss. Retrocochlear pathology could be confirmed in only 2 cases (both from the group with ABR present). Thus, 47 ABRs (15.7% of 299) were false-positive.

Cochlear Diseases↗

PubMed1992

Central projections from singular parts of the vestibular labyrinth in the guinea pig.

Primary afferent projections from singular parts of the vestibular labyrinth were studied in the guinea pig. The posterior ampullary nerve, the common trunk of the anterior and lateral ampullary nerves, as well as fibers innervating the macula sacculi or the macula utriculi were traced with crystals of horseradish peroxidase (HRP) lyophilisate. Posterior, as well as anterior and lateral ampullary fibers were found to project extensively to the superior vestibular nucleus, but also reached the other main vestibular nuclei. Saccular fibers projected mainly to the lateral parts of the lateral vestibular nucleus and to the adjoining descending and superior vestibular nuclei as well as to group y. Modest projections could be followed to the medial vestibular nucleus. Furthermore, a distinct saccular projection to the cochlear nuclei was evident. Utricular projections reached the four main vestibular nuclei with a denser accumulation of fibers within ventral parts of the lateral, descending and superior vestibular nuclei.

Animals↗

PubMed1991

The origin of the vestibulo-cochlear projection in the guinea pig.

Previous tracer studies have revealed the sacculus to be connected to the vestibular and cochlear nuclei in the guinea pig. Due to its own innervation pattern, an anterior and posterior part of the sacculus can be distinguished. The present study investigated whether the two parts differ concerning their fiber contribution to the vestibulo-cochlear projection. After tracing the nerve of the posterior sacculus with horseradish peroxidase (HRP), the vestibulo-cochlear fibers were clearly recognizeable and showed distinct terminal labeling within the cochlear nuclei. In contrast, no terminals were identified in the cochlear nuclei after tracing the anterior sacculus. These results may further substantiate the guinea pig vestibulo-cochlear projection as a central pathway for saccular acoustic sensation.

Afferent Pathways↗

PubMed1991

Saccular afferents to second-order cochlear neurons. An horseradish peroxidase and immunocytochemical study.

Previous studies have described a primary afferent vestibular projection to second-order cochlear neurons originating from the saccular maculae. As could be shown in the guinea pig by means of anterograde transport of horseradish peroxidase and immuno-cytochemistry, these saccular afferents terminated at cells immunoreactive to glutamate and aspartate but not to gamma-aminobutyric acid (GABA). These were intermingled among the fibers of the acoustic striae and situated between the dorsal cochlear nucleus and the octopus cell area. Within the acoustic striae, these saccular afferents appear to have a close relationship to GABA-immunoreactive structures, such as boutons en passant and terminal boutons. This striking relationship, along with cytoarchitectural criteria and the saccular input to these second-order cochlear neurons, gave reason to discern them as a separate cell group.

Afferent Pathways↗

PubMed1990

Optimizing of electroneuronography of the facial nerve.

The amplitude ratio between the paretic and the normal side as determined by electroneuronography is used as a basis for estimating the prognosis of facial palsy. Several methods have been described of placing the surface electrodes and of finding the supramaximal impulse strength. We investigated 16 normal test persons with the aim (1) of optimizing the procedure of neuronography with regard to the possible variations of electrode placement and stimulus intensity and (2) of finding out the right/left difference in normal test subjects. Following our results, the best positions of the recording electrodes are the nasal alae. Even under these most favorable test conditions we found an average side difference of the bilaterally recorded electroneurograms of normal test persons of 22%.

Adult↗