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Biomedical subjects

F Riedel

Publications and source records attributed to F Riedel.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Follicular dendritic reticulum cell sarcoma in a cervical lymph node].

Follicular dendritic cells (FDC) constitute an essential component of B cell follicles, normally serving as antigen-presenting cells and as cells regulating the germinal center reaction. FDC sarcoma is a very rare tumor. We report the case of a 55-year-old male patient who showed persistent cervical lymph node swelling. On biopsy the tumor consisted of spindle cells with nuclear atypia. Immunophenotypic investigation of the tumor tissue revealed a FDC sarcoma of a cervical lymph node. The tumor cells were characterized immunohistochemically especially by the expression of CD21 and focal expression of CD68. In conclusion, FDC sarcoma has to be considered in cases of tumors of uncertain origin in cervical lymph nodes, tonsils, soft palate, or nasopharynx. For clinical practice, it is important to note that sarcomas in cervical lymph nodes are not necessarily metastases but can be primary tumors.

Biopsy↗
PubMed2001

[Anti-angiogenesis - a therapy concept in the treatment of head and neck carcinomas? A review].

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy that is now the sixth most common neoplasm in the world. Despite numerous advances in treatment, the long-term survival has remained the same for the last 25 years. Angiogenesis has been shown to be important for HNSCC tumour growth and metastasis. Therefore, inhibitors of angiogenesis are a new class of anti-neoplastic substances that might be a powerful complement to conventional therapy in HNSCC. MATERIAL AND METHODS: The role of angiogenesis in HNSCC as well as preclinical and clinical trials concerning inhibitors of tumor-angiogenesis are discussed here. RESULTS: Many of the investigated angiogenesis inhibitors demonstrated anti-tumor effects in preclinical and clinical trials. In a few cases, partial remission was observed. CONCLUSIONS: Anti-angiogenic therapy will undoubtly have the potential to change standard tumor therapies. Some anti-angiogenic substances appear to be promising candidates for a clinical use in the therapy of HNSCC.

Adult↗
PubMed2001

The relationship between allelic imbalance on 17p, p53 mutation and p53 overexpression in head and neck cancer.

The huge majority of head and neck squamous cell carcinoma (HNSCC) show alterations of p53 either on the genetic level or on the protein level. Allelic imbalance (AI)/loss of heterozygosity (LOH) on 17p at the p53 locus is frequent in HNSCC. However, the complex relationship between these phenomena is poorly understood in HNSCC. We investigated one group of 39 HNSCC for: a) allelic imbalance on 17p using 4 microsatellite markers located throughout this chromosomal arm; b) mutations of p53 in exons 5-9; and c) overexpression of p53 using two antibodies located on opposite ends of the protein. AI/LOH was detected in 44% at the locus TP53, rising to 69% when regarding all 4 markers on 17p. Therefore, our data are in line with the assumption of additional tumour suppressor genes on 17p in HNSCC. A nuclear accumulation of p53 (51%) was independent from the antibody and the recognised epitope. At the first glance there was no correlation between overall p53 mutation (36%) and overexpression. However, it appeared that, with very few exceptions, only nonsense mutations did not lead to p53 overexpression, while missense mutations did. As overexpression of p53 was 15% more frequent than p53 mutations and only 35% of the tumours with p53 overexpression carried a p53 mutation, our data support the hypothesis of additional mechanisms of p53 overexpression. AI/LOH at the p53 locus in 83% of all tumours with a p53 mutation is in line with Knudson's theory of inactivation of tumour suppressor genes.

Allelic Imbalance↗
PubMed2000

Delayed anterior ischemic optic neuropathy after neck dissection.

There are only 2 published cases of anterior ischemic optic neuropathy (AION) occurring after neck dissection, to our knowledge. We report a case of bilateral AION following neck dissection, discuss the differential diagnoses, and compare the features of this case with those of previously described cases. There were none of the previously described risk factors for the development of AION after head and neck surgery (eg, hypotension, facial edema, or sudden massive hemorrhage) in this case, but there was prolonged diffuse postoperative bleeding. Also, the symptoms did not arise before the fifth postoperative day as they did in the other cases. Prolonged, mild postoperative bleeding is a risk factor for AION. Visual loss during the entire first postoperative week has to be regarded as a complication of surgery, requires the exclusion of several differential diagnoses, and must not be confounded with the patient's confusion or symptoms of withdrawal.

Adult↗
PubMed2000

Expression of basic fibroblast growth factor protein and its down-regulation by interferons in head and neck cancer.

BACKGROUND: Angiogenesis is crucial for tumor growth and metastasis. In several tumors, microvascular density has been shown to correlate with metastasis and aggressiveness. Basic fibroblast growth factor (bFGF) has potent angiogenic activity and has been identified in a wide variety of malignancies including head and neck squamous cell carcinomas (HNSCC). Material and Methods Frozen sections of 50 HNSCC were immunostained for von Willebrand factor and bFGF. Microvessels were counted by light microscopy; bFGF expression was studied at the light and electron microscopic level. Laryngeal cancer cell line HlaC79 was incubated with interferon (IFN) alpha and beta. bFGF quantification was performed by ELISA, and antiproliferative effects were determined by BrdU assay. RESULTS: The mean number of blood vessels (77.5 +/- 23.7) is significantly increased in HNSCC compared with controls (17.1 +/- 5.9). bFGF protein expression was detected in all HNSCC but not in control tissue. An correlation between bFGF expression and mean number of microvessels was found (p <.001). However, no correlation between bFGF expression and the main clinicopathologic features was shown. The long-term exposure (144 hr) of HNSCC cells to noncytostatic concentrations of IFN alpha and beta (>10 U/mL) down-regulated the protein production of bFGF. CONCLUSION: bFGF expression and angiogenesis are enhanced in HNSCC. The higher microvessel density in HNSCC with strong bFGF expression supports the importance of bFGF for tumor angiogenesis. IFN alpha and beta treatment leads to a down-regulation of bFGF expression independent of their antiproliferative effects, suggesting that IFN treatment might result in a reduction of angiogenesis in HNSCC.

Adult↗
PubMed2000

[Use of an intraoral snoring therapy device of thermolabile plastic].

Oral appliances are used to treat snoring and sleep apnea. Yet, their success cannot be predicted without a therapeutical trial. This uncertainty and the high prices of the appliances are the reasons for their limited use. We tested a cheap, custom fit mandibular advancement device (SnorBan) for the treatment of sleep disordered breathing in order to assess its efficacy. 39 consecutive patients (51.1 +/- 9.2 years, BMI = 27.4 +/- 4.5 kg/m2) with different degrees of sleep disordered breathing (AHI = 16.6/h +/- 15.6/h) received the device after a thorough clinical examination. After getting used to the device a second polysomnography was performed. The AHI improved significantly from 16.6/h to 8.2/h (P < 0.01) in the whole group. The only patient who became worse could not get used to the device. Time with snoring dropped significantly from 16.3% to 6.6%, 59.1% of the sleep apnea patients were successfully treated as their RDI dropped below 10/h. The sleep efficiency remained unchanged. Slow wave sleep and REM-sleep increased significantly from 12% to 16% (P < 0.05). The overall compliance was 75%. The custom fit mandibular advancement device Snorban is a cheap and effective treatment for a number of patients with snoring and sleep apnea. The oral appliance is proven to be a useful and simple, non-surgical treatment option. Polysomnographic follow-up is mandatory as breathing may worsen with the device while asleep.

Adult↗
PubMed2000

Serum levels of vascular endothelial growth factor in patients with head and neck cancer.

Angiogenesis is now considered to be crucial for tumor growth and metastasis. In several tumors, microvascular density has been shown to be correlated with metastasis and aggressiveness. Vascular endothelial growth factor (VEGF) is a secreted endothelial cell-specific mitogen, which is induced by hypoxia and is angiogenic in vivo. VEGF has been identified in a wide variety of malignancies including head and neck squamous cell carcinomas (HNSCC). We investigated the circulating level of VEGF in sera from patients with various head and neck squamous cell carcinomas (n = 71) as well as from healthy normal controls (n = 47). Serum VEGF concentrations were determined as serum immunoreactivity by using a quantitative sandwich enzyme immunoassay technique. For statistical analysis, the Wilcoxon 2-sample test and Kruskal-Wallis test were performed. The majority of the patients with HNSCC were found to have high concentrations of serum VEGE The levels of VEGF in the sera of patients with cancer ranged from below the detection limit to 937.1 pg/ml (mean, 144.5 pg/ml). In contrast, the VEGF serum levels in 47 healthy individuals ranged from below the detection limit to 168.1 pg/ml (mean, 32.7 pg/ml), VEGF serum concentration being significantly higher in HNSCC patients (P = < 0.001). These findings indicate that a positive angiogenesis regulator such as VEGF might function as an endocrine growth factor, particularly for solid HNSCC tumors and may be a useful marker for clinical monitoring.

Adult↗
PubMed2000

Salivary gland carcinosarcoma: immunohistochemical, molecular genetic and electron microscopic findings.

Salivary gland carcinosarcoma, or true malignant mixed tumor, is a very rare and extremely aggressive neoplasm. The clonality and clonal origin of this tumor are discussed controversially. We report a carcinosarcoma of the left parotid gland in a patient who subsequently died of cutaneous, lymphatic and pulmonary metastases. Immunohistochemical staining, electron micrograph analysis, loss of heterozygosity (LOH) analysis and sequence analysis were performed on this tumor with an adenocarcinomatous and a predominant spindle cell-like component. While smooth muscle actin was undetectable by immunohistochemistry, cytoplasmatic myoepithelial structures could be detected by electron microscopy. LOH analysis at 12 genomic locations detected complete deletion of one allele at 17p13.1, 17q21. 3, and 18q21.3 indicating allelic loss in both components of the tumor. Double strand sequencing of the remaining allele of the p53 tumor suppressor gene revealed a wild-type allele. Based on our results, we favor the hypothesis of monoclonal origin of this salivary gland carcinosarcoma with a common stem cell that could be the myoepithelial cell and an inactivated tumor suppressor gene on chromosome 17 other than p53.

Aged↗
PubMed2000

[Coexpression of VEGF and bFGF is associated with increased vascular density in head and neck carcinomas].

BACKGROUND: Angiogenesis is crucial for tumor growth and metastasis. In several tumors, microvascular density has been shown to correlate with metastasis and aggressiveness. Vascular endothelial growth factor (VEGF) and basic Fibroblast Growth Factor (bFGF) are known to have potent angiogenic activity. Their expression has been identified in a wide variety of malignancies including head and neck squamous cell carcinoma (HNSCC). Aim of our study was to investigate the role of co-expression of VEGF and bFGF for angiogenesis in HNSCC. MATERIAL AND METHODS: Cryostat sections of 51 primary HNSCC were immunostained for VEGF and bFGF using a standard streptavidin-biotin complex procedure. To evaluate angiogenesis, endothelial cells were stained immunohistochemically using anti-vWF polyclonal antibody. Microvessels were quantified by counting vessels in a x200 field in the most vascular area of the tumor. RESULTS: 25/51 (49%) of the investigated carcinomas showed co-expression of both factors (VEGF+/bFGF+), while 6/51 (11.7%) carcinomas only expressed VEGF and 13/51 (25.5%) carcinomas expressed bFGF. 7/51 (13.7%) tumors showed no expression of these factors (VEGF-/bFGF-). Carcinomas with a co-expression of VEGF and bFGF showed a significantly increased mean microvessel density (88.3 +/- 24.4) compared to tumors expressing only VEGF (77 +/- 16.8) or bFGF (71.1 +/- 15.8) (p = 0.022) or tumors with no expression of both factors (51.1 +/- 13.4) (p < 0.001). The association of VEGF and bFGF expression level was not significant (p = 0.178). CONCLUSIONS: The positive correlation of the co-expression of angiogenic VEGF and bFGF with increased microvessel density underlines the importance of both factors for tumor angiogenesis in HNSCC. VEGF and bFGF might act cooperatively in the process of neovascularization in human head and neck cancer.

Adult↗
PubMed2000

Vascular endothelial growth factor expression correlates with p53 mutation and angiogenesis in squamous cell carcinoma of the head and neck.

Vascular endothelial growth factor (VEGF) has potent angiogenic activity and has been identified in a wide variety of malignancies, including head and neck squamous cell carcinoma (HNSCC). The tumour-suppressor gene p53 has been thought to regulate VEGF. Cryostat sections of 33 head and neck squamous cell carcinomas (HNSCC) were immunostained for VEGF using a standard streptavidin-biotin complex procedure. To evaluate angiogenesis, microvascular density was counted by staining endothelial cells immunohistochemically using anti-vWF monoclonal antibody. The p53 gene status was analysed using a PCR-SSCP analysis and direct sequencing. VEGF positive staining was detected in 18 (55%) out of 33 tumours. VEGF immunoreactivity did not correlate with the main clinicopathological characteristics of the patients (localization, T-stage, N-status, histological grading). Statistical analysis gave a clear correlation between the tumour vascularity and the VEGF protein expression (p = 0.0036). VEGF negative tumours showed a lower mean number of microvessels per microscopic field (60.3 +/- 15.5) than VEGF positive tumours (79.6 +/- 22.9). P53 mutations were identified in 12 (36.4%) of 33 tumours. The association of p53 mutations and VEGF expression level was significant (0.027). The higher microvessel density in VEGF positive tumours supports the importance of VEGF for tumour angiogenesis in HNSCC. Our results support the hypothesis of a p53 regulation on the angiogenic process through a VEGF up-regulation.

Adult↗
PubMed2000

Sleep apnea syndrome in patients with cardiac pacemaker.

BACKGROUND: Heart rhythm disturbances are cardiac side effects in patients with sleep-disordered breathing (SDB), which in itself is considered to be a risk factor for bradycardic rhythm disturbances. OBJECTIVE: We analyzed the prevalence and degree of SDB in patients who received a cardiac pacemaker due to bradycardic rhythm disturbances and investigated the relationship between the severity of an underlying SDB and the type of heart rhythm disturbance. METHODS AND RESULTS: 192 patients (100 males, 92 females, mean age 62.2 +/-12.2 years) were studied using the portable screening device MESAM IV. The respiratory disturbance index (RDI) was calculated visually. The mean RDI in all patients was 9.13+/-11. 09/h, 11.7+/-13.15/h in males and 6.33+/-7.42/h in females. The prevalence ratio of SDB between men and women was 1.7:1, with significant differences in the respective severity (p<0.05). The screening showed a prevalence of SDB (RDI >10/h) of 32.3%. The highest prevalence was found in the group of patients with atrial fibrillation and bradycardia. However, there were no significant differences compared to other types of rhythm disturbances. The RDI in the population studied depended on age and body mass index, but not on the existence or type of rhythm disturbance and not on concomitant diseases. CONCLUSION: The prevalence of SDB in cardiac pacemaker patients is similar to that in patients of comparable age without a pacemaker. A heart rhythm disturbance does not seem to be an independent risk factor for development of SDB. Nevertheless, the differential diagnosis of bradycardic rhythm disturbances in this age group should include a screening for sleep apnea.

Age Distribution↗
PubMed2000

Argon plasma coagulation for inferior turbinate reduction.

Surgical reduction of the inferior turbinate remains a widely used therapy for nasal obstruction caused by hyperplastic turbinates. Current methods are costly and time-consuming, require nasal packing, and cause extended postoperative swelling. Argon plasma coagulation (APC) is a new, innovative technique in otorhinolaryngological surgery that is based on high-frequency electrical current. The current is transmitted through ionized argon gas (plasma) contact-free to the tissue surface and creates a coagulation and devitalization zone with limited penetration. Forty-five patients with nasal obstruction were treated under local anesthesia for reduction of the inferior turbinates with APC. Seventy-six percent of the patients reported an improvement of postoperative swelling within the first week. After 3 months, 86% reported having better nasal airflow than they had before the operation. Macroscopically, after 4 weeks the turbinate was covered by normal mucosa in 51% of the patients. Crust formation was minimal, and no bleeding occurred. Turbinate reduction with APC is an alternative technique with many advantages, and the results are comparable to those of standard techniques. Ninety-five percent of the patients were satisfied with the operation.

Argon↗
PubMed2000

Expression of 92-kDa type IV collagenase correlates with angiogenic markers and poor survival in head and neck squamous cell carcinoma.

MMP-9, which degrades extracellular matrix, is believed to play a crucial role in tumor invasion and metastasis. Angiogenesis is also perceived as an important step in tumor growth and metastasis. The aim of this study was to investigate the expression of MMP-9 in tumor samples of HNSCC patients and to study a possible correlation to angiogenic markers. Cryostat sections of 52 HNSCC tumors were immunostained for MMP-9, bFGF and VEGF using a standard streptavidin-biotin complex procedure for light microscopic investigation. Microvessel density (MVD) was determined by staining of endothelial cells immunohistochemically using anti-vWF monoclonal antibody. MMP-9 positive staining was detected in 27/52 (52%) of the tumors. MMP-9 immunoreactivity did not correlate with the main clinicopathological characteristics of the patients (localisation, T-stage, N-stage, histological grading), but correlated with worse survival of the patients. MMP-9 negative tumors showed a significant lower mean MVD per microscopic field than MMP-9 positive tumors (p<0. 001). There was a significant association of MMP-9 and VEGF expression (p<0.05). The presence of MMP-9 in HNSCC cancer and the positive correlation with MVD and VEGF expression supports the theory that MMP-9 functions as a regulator of tumor angiogenesis supporting endothelial cell invasion. MMP-9 and VEGF might act co-operatively in the process of neovascularization in human head and neck cancer.

Adult↗
PubMed1999

A genome-wide search for linkage to asthma. German Asthma Genetics Group.

Asthma is among the most frequent chronic diseases in childhood. Although numerous environmental risk factors have already been identified, the basis for familial occurrence of asthma remains unclear. Previous genome screens for atopy in British/Australian families and for asthma in different American populations showed inconsistent results. We report a sib pair study of a sample of 97 families, including 415 persons and 156 sib pairs. Following an extensive clinical evaluation, all participants were genotyped for 351 polymorphic dinucleotide markers. Linkage analysis for asthma identified four chromosomal regions that could to be linked to asthma: chromosome 2 (at marker D2S2298, P = 0.007), chromosome 6 (around D6S291, lowest P = 0.008), chromosome 9 (proximal to D9S1784, P = 0.007), and chromosome 12 (D12S351, P = 0.010). These linkage regions could be reproduced for all loci by analysis of total or specific immunoglobulin E (minimum P values at these regions were 0. 003, 0.001, 0.010, and 0.015, respectively).

Asthma↗
PubMed1999

[Detection of serum concentration of carbohydrate-deficient transferrin (CDT) in patients with head-neck carcinomas].

It is now well known that chronic alcohol abuse is an important factor for developing head and neck squamous cell carcinoma (HNSCC). While hospitalized, these patients are at great risk for developing an unexpected alcohol-withdrawal syndrome. Compared to common markers of alcohol abuse, carbohydrate-deficient transferrin (CDT) has been found to be more sensitive and specific. It is therefore very useful for detecting alcoholism and controlling compliance of alcohol withdrawal. We analyzed the serum concentrations of CDT, liver enzymes and mean corpuscular volume in 49 male patients with HNSCC. Elevated CDT levels were found in more than 25% of patients who earlier denied a history of chronic alcohol abuse. Over one-third of these patients developed an alcohol-withdrawal syndrome. These findings demonstrated that analysis of elevated CDT serum levels was a valuable method for detecting chronic alcohol abuse and recognizing patients at risk for developing an alcohol-withdrawal syndrome post-operatively.

Alcohol Drinking↗
PubMed1999

[Controlled cosmetic dermal ablation in the facial region with the erbium:YAG laser].

The erbium: YAG laser (wavelength 2940 nm; pulse duration 0.350 ms; pulse energy 0.1-1.7 J) allows vaporization of very thin skin layers without scarring and minimal lateral thermal injury due to an extremely short pulse duration. It permits exact ablation of relatively large areas of facial skin. We report our results with 216 patients following treatment for different facial lesions (facial wrinkles, acne scars, syringomas, and circumscribed sebaceous gland hyperplasia) using a new erbium: YAG laser system. Good-to-excellent cosmetic results were obtained in these patients. Our findings show that the erbium: YAG laser is an elegant and promising new method for the treatment of facial lesions.

Cicatrix↗