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K Neumann

Publications and source records attributed to K Neumann.

At least 19 recordsLinked to original sources
PubMed2007

[Stomal metastases after translaryngeal tracheotomy (TLT) according to Fantoni: a rare complication].

The translaryngeal tracheotomy (TLT) according to Fantoni with rigid endoscopy is well known and easy to execute. In our department we have used this method since 2002. In 17 patients suffering from carcinomas of the upper aerodigestive tract, we performed a TLT. Peri- and postoperative complications were examined. In 17 patients there were no intraoperative complications. As an early complication we found in one case a dislocation of the tracheostomy tube postoperatively. In one patient we observed metastases in the prior TLT stoma as a major late complication. Another patient also probably suffered from metastases in the prior TLT stoma. We did not find tracheoesophageal fistulas or stenosis of the trachea. Iatrogenic neoplastic seeding of squamous cell carcinomas of the upper aerodigestive tract is a serious complication. Our experience with these two cases and a review of the literature indicates that in patients with head and neck cancer, pull procedures for placement of TLT tubes may induce metastases by direct implantation of tumor cells because of contact between the TLT tube and the primary tumor cells. TLT according to Fantoni cannot be recommended for the treatment of cancer of the upper aerodigestive tract. Methods of tube insertion that avoid such contact, e.g., Ciaglia, surgical tracheostomy, should be preferred.

Aged↗
PubMed2006

Identification and analysis of putative regulatory sequences for the MYF5/MYF6 locus in different vertebrate species.

The myogenic factors (MYF) 5 and 6 are integral to the initiation and development of skeletal muscle and to the maintenance of its phenotype. Thus, they are candidate genes for growth- and meat quality-related traits. We performed a comparative sequence analysis of the MYF5/MYF6 locus in swine, cattle, dog, chicken and zebrafish on the basis of structural and functional information from human and mouse. Beside the characterization of upstream regulatory elements recently identified in mice, we demonstrate the existence of further highly conserved elements (E1 to E4) which may play a role in the regulation of MYF5 and MYF6 expression. Comparative sequence analysis of putative regulatory sequences in swine revealed a total of 21 single nucleotide polymorphisms (SNP) including 1 and 6 SNPs new for the promoters of MYF5 and MYF6, respectively. The conserved organization of the locus in vertebrates indicates a common basic mechanism of muscle development. However, the existence of numerous regulatory elements at large distances to MYF5 and MYF6 points to a very complex pattern of the gene regulation with significant differences between species.

Animals↗
PubMed2006

Effects of luting agent and thermocycling on bond strengths to root canal dentine.

AIM: To investigate the effects of luting agent and thermocycling on bond strengths to root canal dentine. METHODOLOGY: Extracted maxillary canines (n =144) were root filled and divided into six groups of 24 teeth each. Fibre posts (FRC Postec) were inserted using six luting agents: Panavia F, Multilink, Variolink II, PermaFlo DC, RelyX Unicem and Clearfil Core. Each root was sliced into six discs (thickness 1 mm) representing the coronal, middle and apical part of the root canal. Push-out tests were performed 24 h after post insertion (n = 12) as well as after thermocycling (5000x; 5-55 degrees C, 30 s) (n = 12). Statistical analysis was conducted using analysis of variance (anova) followed by post-hoc comparisons (Tukey-B). The influence of thermocycling on bond strengths was investigated for each material and region separately using t-tests. RESULTS: The bond strengths were significantly affected by the luting agent (P < 0.001), the root position (P = 0.003) and thermocycling (P < 0.001; three-way anova). RelyX had significantly higher bond strengths compared with all other materials (P < 0.05; Tukey-B). The apical region of the root canal had significantly higher bond strengths compared with the middle and coronal region (P < 0.05; Tukey-B). After thermocycling for RelyX a significant increase in bond strengths was detected for the middle and apical region (P < 0.01; t-test, Bonferroni factor 18). CONCLUSIONS: Bond strengths were affected significantly by luting agent and root position. RelyX had higher bond strengths compared with other materials. The apical region of the canals was characterized by significantly higher bond strengths.

Analysis of Variance↗
PubMed2006

Risk and predictors of early epileptic seizures in acute cerebral venous and sinus thrombosis.

We assessed the risk and determined predictors of early epileptic seizures (ES) in patients with acute cerebral venous and sinus thrombosis (CVST). A prospective series of 194 consecutive patients with acute CVST admitted to neurological wards in two German university hospitals was analysed for frequency of ES and in-hospital mortality. Demographic, clinical and radiological characteristics during the acute stage were retrospectively analysed for significant association with ES in univariate and multivariate analyses. During the acute stage, 19 patients (9.8%) died. Early symptomatic seizures were found in 86 patients (44.3%). Status epilepticus occurred in 11 patients (12.8%) of whom four died. Amongst patients with epileptic seizures, mortality was three times higher in those with status than in those without (36.4% and 12%, respectively). In multivariate logistic regression analysis, motor deficit [odds ratio (OR) 5.8; 95% CI 2.98-11.42; P < 0.001], intracranial haemorrhage (OR 2.8; 95% CI 1.46-5.56; P = 0.002) and cortical vein thrombosis (OR 2.9; 95% CI 1.43-5.96; P = 0.003) were independent predictors of early epileptic seizures. Status epilepticus was an important source of morbidity and early mortality in patients with CVST in this study. Patients with focal motor deficits, cortical vein thrombosis and intracranial haemorrhage carried the highest risk for ES. Prophylactic antiepileptic treatment may be an option for these patients.

Adolescent↗
PubMed2005

[Sclerotherapy with OK-432 for cystic tumors in the neck region].

BACKGROUND: The intralesional injection of OK-432 has been proposed as an effective treatment of lymphangiomas and ranulas. The aim of this study was to review our experience with sclerotherapy of benign cervical cysts as an alternative method to surgical extirpation. PATIENTS AND METHODS: We performed a case note review of six patients who received OK-432 injections in a concentration of 0.01 mg/ml between March 2002 and December 2003. RESULTS: Disappearance of the lesions was achieved after one to three injections in all patients. We found a complete remission in two of six patients and a marked reduction in four of six patients. There were no significant complications observed. CONCLUSION: OK-432 is an effective alternative in the treatment of benign cervical cysts, but it is very important to exclude malignancy-associated diseases before instillation of OK-432. Long-term results will be awaited.

Adolescent↗
PubMed2005

[Orbital foreign bodies -- diagnostics, therapy and management].

BACKGROUND: Orbital foreign bodies constitute an interdisciplinary challenge, diagnosis being especially difficult because of inconspicuous entrance orifices. Indication for the removal of an orbital foreign body has always to be decided upon individually taking into account the benefits and risks resulting from an operation. The latter is particularly indicated if there are acute and chronic functional restrictions or inflammatory reactions either present or to be expected. The objective of our study was to produce systematic guidelines concerning the therapeutic procedure of dealing with orbital foreign bodies with a view to a benefit-risk assessment. PATIENTS AND METHODS: Over the last ten years ten patients with an orbital foreign body were treated in our Department, four of them requiring acute attention. CTs were taken of all patients. Only in one case additional MRTs were produced. Eight out of ten patients underwent operation, of which seven resulted in a complete removal of the foreign body. In the case of two patients we decided against an operation after interdisciplinary consultation. RESULTS: In our view the imaging--providing diagnostics by means of computer tomography is the most promising method for determining a foreign body in the orbit. Decision for an operative removal of a foreign body was invariably taken interdisciplinary in cooperation with an ophthalmologist. Surgical approach was chosen in accordance with the localisation of the foreign bodies. None of the patients suffered from a loss of vision or a restriction of functions as a result of the operation. CONCLUSIONS: In the indication the foreign material is of essential importance. Orbital foreign bodies that have been present in the tissue for a longer time can be allowed to stay, unless loss of functions are progressive. Loss of vision always being a consequence of the initial trauma.

Adolescent↗
PubMed2005

Genetic spatial structure of European common hamsters (Cricetus cricetus)--a result of repeated range expansion and demographic bottlenecks.

The spatial genetic structure of common hamsters (Cricetus cricetus) was investigated using three partial mitochondrial (mt) genes and 11 nuclear microsatellite loci. All marker systems revealed significant population differentiation across Europe. Hamsters in central and western Europe belong largely to two allopatric mitochondrial lineages south and northwest of the Carpathian and Sudetes. The southern group, 'Pannonia', comprises populations inside the Carpathian basin (Czech Republic, Hungary) while the second group, 'North', includes hamsters from Belgium, the Netherlands, France, and Germany. Isolation of the lineages is maintained by a combination of geographical and ecological barriers. Both main phylogeographical groups show signs of further subdivision. North is separated into highly polymorphic central German and less polymorphic western populations, which most likely split during late glacial expansion (15,000-10,000 bp). Clock estimates based on haplotype distributions predict a divergence of the two major lineages 85,000-147,000 bp. Expansion times fall during the last glaciation (115,000-10,000 bp) corroborating fossil data, which identify Cricetus cricetus as characteristic of colder climatic phases. Despite the allopatry of mt haplotypes, there is an overlap of nuclear microsatellite alleles between phylogeographical units. Although there are strong evidence that Pannonian hamsters have persisted inside the Carpathian basin over the last 50,000 years, genetic differentiation among European hamsters has mainly been caused by immigration from different eastern refugia. Possible source populations are likely to be found in the Ukrainian and the southern Russian plains--core areas of hamster distribution. From there, hamsters have repeatedly expanded during the Quaternary.

Animals↗
PubMed2004

Bronchial reactivity in hyperresponsive patients and healthy individuals: demonstration with high resolution computed tomography.

OBJECTIVE: High resolution computed tomography (HRCT) was used to assess the extent of bronchial reactivity after inhalative bronchoprovocation and dilation in hyperresponsive patients and healthy subjects. PATIENTS AND METHODS: Patients with mild intermittent asthma, 15 with a >20% decrease in FEV1 and a >10 mmHg (PC20+) in PaO2, 12 with a <20% decrease in FEV1 and a >10 mmHg (PC20-) in PaO2 after provocation, and eight healthy humans were included in the study. Changes in cross-sectional area in a total of 1256 bronchi and in bronchial wall area (792 bronchi) were evaluated after histamine-triggered bronchoprovocation and salbutamol-induced bronchodilation at high lung volumes (FVC 80%). Data were compared with the results of pulmonary function tests (FEV1, PaO2, PaCO2). RESULTS: In all groups, a significant decrease in bronchial cross-sectional area (P<0.001) and a significant increase in bronchial wall area (P<0.001) were observed subsequent to bronchoprovocation. After bronchodilation, the increase in cross-sectional area (P<0.001) and the further increase in airway wall area (P<0.01) were significant in all groups. In PC20+ and PC20- asthmatics, significant differences (P<0.05) in PaO2, >10 mmHg between baseline and provocation were observed. In healthy persons, the PaO2 decrease was <10 mmHg (P>0.05). After histamine provocation, the decrease in FEV1 was measured in the PC20+ group, whereas a <20% FEV1 decrease was found in the PC20- and the control groups, respectively. No significant correlations were observed between radiological data and the results of pulmonary function tests. CONCLUSIONS: HRCT demonstrated bronchial reactivity in hyperresponsive patients and, unexpectedly, in healthy subjects. The applied pulmonary function tests failed to characterize bronchial reactions in the healthy subjects. Based on these results, HRCT is a useful tool by which to achieve a comprehensive understanding of the pathophysiological processes in asthmatic patients.

Adolescent↗
PubMed2004

[HRCT and bronchial asthma: visualization of the pathophysiologic changes of the pulmonary parenchyma after inhalation provocation].

PURPOSE: To characterize parenchymal lung affections morphologically in patients with asthma and healthy subjects by high -resolution computed tomography (HRCT) subsequent to histamine-triggered inhalation bronchoprovocation and salbutamol-induced broncholysis, and to compare the results with pulmonary function tests. MATERIALS AND METHODS: Fifteen asthmatics with bronchial hyperreactivity, with a > 20% decrease in FEV1 and a > 10 mmHg decrease in PaO(2) after bronchoprovocation (PC20%+), twelve asthmatics with a < 20% decrease in FEV1 and a > 10 mmHg decrease in PaO(2) after bronchoprovocation (PC20%-), and eight healthy persons without bronchial hyperreactivity underwent inhalation bronchoprovocation and broncholysis. Spirometer-triggered HRCT at high lung volumes was performed, and total and peripheral lung densities and the amount of solid lung structures, representing predominantly vessels, were measured. RESULTS: After bronchoprovocation, we observed significant decreases in total and peripheral lung densities in all groups (p < 0.0005), and a significant increase in lung densities subsequent to bronchodilation (p < 0.0002). The morphological alterations in solid lung structure were not significantly different after bronchoprovocation or broncholysis (p > 0.05), as compared to the baseline measurements. In hyperreactive patients, PaO(2) significantly decreased after provocation and significantly increased after lysis (p < 0.05). In PC20%+ asthmatics, a mean reduction of 27.8% in FEV1 was observed, which was < 20% in the other groups. No significant correlations were observed between radiological data and the results of pulmonary function tests. In healthy persons, we demonstrated highly significant parenchymal response to bronchoprovocation and broncholysis, which was not otherwise documented by pulmonary function tests. CONCLUSION: In both PC20%+ and PC20%- patients as well as in healthy individuals, HRCT was efficient in the evaluation of pathoanatomical alterations of the lung parenchyma subsequent to inhalation provocation. In healthy individuals, these parenchymal alterations were not documented by pulmonary function tests.

Adult↗
PubMed2003

[Malignant schwannoma of the trachea].

Malignant schwannoma of the trachea is a rarity among the infrequent neurogenic tumours of the cervical region. Only individual cases have been described in the literature to date. A 30-year-old patient came to us with acute dyspnoea. A bronchoscopy showed a polypoid-stemmed tumour, which was removed using a loop. Histologically, it was a malignant neurogenic tumour of a low-grade schwannoma nature. A tracheal segment resection was carried out to remove the tumour completely. Six years after the operation, the patient was still recurrence-free. The prognosis depends on whether a high or low grade malignant schwannoma is present. The histological grading of the neurogenic peripheral neurilemmoma is made depending on a number of histological parameters and is often rather difficult. Specialists agree that only the radical surgical removal of the tumour might lead to patient's recovery. Adjuvant measures like chemo- or radiotherapy do not significantly prolong the life expectancy.

Adult↗
PubMed2003

[Fibrous dysplasia of the petrous bone].

Fibrous dysplasia named after Jaffè and Lichtenstein is a benign, self-limiting disorder of the bone structure. The normal bone is replaced by cellular fibrous connective tissue. Fibrous dysplasia can be differentiated into monostotic and polyostotic forms and the McCune-Albright syndrome (combination of polyostotic areas in the bone with hyperpigmentation of the skin and endocrinological disturbances). The rare disease is predominantly found in the 1st to 3rd decade of life in the femur or humerus. In about 15% of all cases it affects the facial bones, and one-third of these is located in the jaw bone. Extremely rare is the invasion of the petrous bone. A 45-year-old female patient was examined because of tinnitus persisting for 1 year. In addition, she was suffering from increased hearing reduction and recurrent vertigo. The CT and MRT showed a milky glass-like tumor, which was limited by an osteolytic process situated in the left petrous bone. The process was removed via the mastoid. Histological examination revealed fibrous dysplasia. A highly differentiated osteosarcoma and an ossifying fibroma as important differential diagnoses have to be excluded because of the different therapeutic consequences.

Cerebellopontine Angle↗
PubMed2003

[Operative voice pitch raising in male-to-female transsexuals. A survey of our technique and results].

BACKGROUND: Transsexuality constitutes a complex,permanent transposition due to a paradoxical sense of belonging to the opposite sex. The persons concerned experience such a high degree of suffering that they strive to undergo operative sex reversal. Mainly in the case of male-to-female transsexuals this may often lead to a subsequent discrepancy between the external appearance and the character of the voice,since only a deepening of the voice can be achieved by hormonal treatment and not a raising of its pitch.Also,logopedic treatment on its own cannot,as a rule, guarantee a lasting success. In order to adapt the voice as an essential aspect of human identity to the external female appearance,a variety of phonosurgical operation techniques have been developed since the seventies. PATIENTS AND METHODS: In 1993 a modified cricothyroidal approximation via miniplates, following ISSHIKI's technique, has been performed at the ENT Department of the Martin-Luther-University of Halle-Wittenberg. This procedure is based upon an approximation of the cricoid and thyroid cartilages resulting in an increase in the vocal cord tension. This intervention does not affect the inner structures of the larynx and is on principle reversible. Combined with a chondrolaryngoplasty it allows for a reduction of the Adam's apple. So far 57 patients have undergone this surgical intervention. Laryngoscopy, stroboscopy and a detailed voice diagnostic, as well as ultrasound and computertomographic examinations of the larynx are performed pre and postoperatively in order to record the anatomical-physiological and functional data. RESULTS AND CONCLUSIONS: So far good functional results could be achieved showing an average rise of the medium voice range by approximately one fourth. As a long-term result a permanent raising of the basic voice pitch has been reported. The majority of the patients are satisfied with the functional and cosmetic effect reporting an enhanced self-esteem.

Adult↗
PubMed2003

Objective evaluation of the relative modulation transfer function of densitometers for digitisation of electron micrographs.

Digitisation of images recorded on film is a crucial part of data acquisition in electron microscopy, particularly for electron cryo-microscopy of biological specimens where the contrast and signal-to-noise ratio are low. A quantitative method to evaluate and compare the quality of densitometers, as measured by the modulation transfer function (MTF), is described here. The densitometer is modelled as a linear system, the output being the convolution of the input image and a point spread function. The MTF is the magnitude of the Fourier transform of the point spread function. The relative MTF describes the quality of signal transfer with spatial frequency. It is important that fine structural details in the micrograph are digitised with a high value for the MTF which does not vary with direction. A test pattern has been generated by projecting an electron image of a grid pattern onto film. The film is scanned and a computer program measures the intensities of the diffraction orders of the repeating pattern. Three different scanners are compared, one is a point scanner and the other two are line scanners. The test can be used to check if a scanner is set up optimally, and how it compares with another scanner.

Journal Article↗
PubMed2003

[Resorbable material for osteosynthesis or titanium for the cricothyroidopexy?].

BACKGROUND: The failure of cricothyroid approximation in male-to-female-transsexuals--as described by Isshiki--is often caused by suture cutting through the cartilage early postoperatively. At this stage there is no stabilized scarring and the previously approximated edges of the cartilage can drift apart, lowering the voice pitch through reduction of the tension of the vocal cords. The cartilage can be protected from cutting injuries of the wire sutures by using mini plates made of either titanium or LactoSorb. The present study examined the influence of the different materials on the result. PATIENTS AND METHODS: A cricothyroidopexy in male-to-female-transsexuals was performed in 67 patients between October 1993 and December 2001. The medium age was 39 years, ranging from 24 to 67 years. For stabilizing the thyroid and cricoid cartilage titanium mini plates were used in 28 patients (41.8 %) and LactoSorb mini plates in 39 (58.2 %). A complete voice diagnostic work-up was performed pre- and postoperatively. RESULTS AND CONCLUSIONS: In 94 % of all patients the medium speaking voice could be raised on average by five half tones through the increased tension of the vocal cords. In 39 % very good (rise by more than 12 half tones) and good (rise by six to 12 half tones) results could be achieved, while in 55 % a minimal (one to two half tones) or very small (three to five half tones) rise was noted. The material of the mini plates had no impact on the degree of voice pitch raising, the long-term results or the number of revision surgeries.

Adult↗
PubMed2003

[Clinical experience with percutaneus large-core needle biopsies of the breast and evaluation of cytopathological and histopathological results].

OBJECTIVE: Core needle biopsy (CNB) allows a microinvasive diagnosis of breast lesions. We investigated whether imprint cytology of CNB specimens is a useful method of rapidly obtaining additional diagnostic information. MATERIAL AND METHOD: During five years 46 218 breast examinations for 23 300 patients were performed. 563 patients were examined by CNB. The results of imprint cytology were compared with the histopathological results. Statistical analysis was done for all patients who underwent subsequent surgery. RESULTS: 195 of 563 patients were treated surgically. 155 patients exhibited malign lesions. 40 patients showed benign breast lesions. Four patients with malign findings in imprint cytology and histopathology of CNB were treated conservatively. Imprint cytology had a sensitivity of 0.89, specificity of 0.88, positive predictive value of 0.96 and negative predictive value of 0.67. Histopathology revealed a sensitivity of 0.90, specificity of 0.95, positive predictive value of 0.98 and negative predictive value of 0.70. 364 patients with benign findings in imprint cytology and histopathology were controlled subsequently. One of these patients developed five month later an invasive ductal tumor. CONCLUSION: Imprint cytology of CNB is a reliable method to obtain additional diagnostic information. Inadequate and suspicious cases should be evaluated based on complementary diagnostic procedures for breast lesions.

Adult↗
PubMed2003

[Intralesional cidofovir injections for recurrent laryngeal papillomatosis: first results].

BACKGROUND: The treatment of recurrent laryngeal papillomatosis still presents an important therapeutic problem. This primarily benign disease of the larynx is caused by an infection with the human papilloma virus (HPV) and forms epithelial neoplastic papillomas. Therapy in larynx obstructing papillomatosis usually requires laser ablation. Cidofovir acts virustatically as an nucleosidanalogon. Currently pilot studies investigate the effectiveness of intralesional Cidofovir injection. PATIENTS AND METHODS: The present study covers the period from October 2001 to March 2003. Seven patients, age of five to 70 years, were treated with intralesional injections of Cidofovir after microlaryngoscopic ablation of laryngeal papillomas. In all patients papillomatosis was confirmed histologically and a clinical-phoniatric examination and a photo documentation pre- and postoperatively was carried out. We treated patients to a maximum of six sessions. RESULTS AND CONCLUSIONS: After three to six sessions of laser ablation of the papillomas and intralesional injections with Cidofovir a distinct papilloma reduction could be observed in all patients and in two cases a complete remission was achieved. The follow-up period of seven to 15 months revealed no recurrent laryngeal papillomatosis. The majority of patients showed a defined voice improvement. There were no local or systemic side-effects caused by the virustatic drug. Intralesional injection of Cidofovir appears to develop into a promising adjuvant therapy option in recurrent laryngeal papillomatosis. First results of the study seem to achieve a considerable reduction of the previously high rate of recurrence of laryngeal papillomatosis.

Adolescent↗
PubMed2003

A single point mutation in Drosophila dihydrofolate reductase confers methotrexate resistance to a transgenic CHO cell line.

Sequence analysis of a cDNA encoding dihydrofolate reductase (DHFR) from a selected methotrexate-resistant Drosophila melanogaster cell line (S3MTX) revealed a substitution of Gln for Leu at position 30. Although the S3MTX cells were approximately 1000 fold more resistant to methotrexate (MTX), the karyotype was similar to the parental line and did not show elongated chromosomes. Furthermore, kinetic analysis of the recombinant enzyme showed a decreased affinity for MTX by the mutant DHFR. To determine if the resistance phenotype could be attributed to the mutant allele, Drosophila Dhfr cDNAs isolated from wild type and S3MTX cells were expressed in Chinese hamster ovary (CHO) cells lacking endogenous DHFR. The heterologous insect DHFRs were functional in transgenic clonal cell lines, showing approximately 400-fold greater MTX resistance in the cell line transfected with the mutant Dhfr than the wild type Dhfr. Resistance to other antifolates in the CHO cells was consistent with the drug sensitivities seen in the respective Drosophila cell lines. ELevated Levels of Dhfr transcript and DHFR in transgenic CHO cells bearing the mutant cDNA were not seen. Taken together, these results demonstrate that a single substitution in Drosophila DHFR alone can confer Levels of MTX resistance comparable with that observed after considerable gene amplification in mammalian cells.

Animals↗