Biomedical subjects

S Wenzel

Publications and source records attributed to S Wenzel.

At least 37 records · Page 2Linked to original sources

PubMed2003

[Naphazoline intoxication: course and therapy].

BACKGROUND: As potent alpha-adrenergic agonists imidazoline derivatives like naphazoline are frequently used drugs because of their vasoconstrictive and decongestant properties. Beside their well-known local side effects also rare systemic ones like hypertension, excitability and nausea are possible. In case of intoxication this can enhance to ischemia of vital organs, bradycardia with arrhythmia, respiratory depression, hypothermia, excitation or marked sedation. PATIENTS: Two cases of intoxication after application of naphazoline for haemostasis under the operation, the postoperative course and therapy are reported. RESULTS: No specific antidote is available but a symptomatic drug therapy with intravenous administration of 5 mg phentolamine, an alpha-adrenoceptor antagonist acts against the vasoconstrictive side effects. CONCLUSIONS: Because of the serious side effects and the narrow therapeutic to toxic window of naphazoline a strict observance of guidelines and contradictions, such as maximum dose, is necessary.

Adenoidectomy↗

PubMed2003

[Surgical treatment of rhinophyma with the ultrasonic scalpel (Ultracision Harmonic Scalpel)].

BACKGROUND: There are multiple surgical approaches to the treatment of rhinophyma. Because of the exceptional vascularity of the nose, traditional surgical approaches to the management of rhinophyma are fraught with persistent intraoperative hemorrhage. Hemorrhage that is controlled with electrocautery or laser by a combination of excision of rhinophymatous tissue and simultaneous hemostasis invariably damages cartilage by thermal injury. The UltraCision Harmonic Scalpel achieved a tissue dissection with a simultaneous hemostasis and only minimal thermal tissue injury. To this date, in Europe no studies have been published on the use of the Ultracision Harmonic Scalpel in the surgical treatment of rhinophyma. PATIENTS AND TREATMENT: 6 patients had surgical treatment of rhinophyma with the UltraCision Harmonic Scalpel. The objective of the study was therefore to analyse the handling indication, the efficiency of intra- and postoperative hemostasis, the wound healing, the postoperative pain and the histologic results of tissue resections. RESULTS: Because of the effective intraoperative hemostasis supplementary hemostasis was not required in any examined patient. The efficient hemostasis and the tactile experience of the UltraCision Harmonic Scalpel enabled an accurate sculpting of the nose. Postoperative pain sensation was minimal. Wound healing was uneventful in all cases. Postoperative reepithelialization occurred within 28 days. Delayed complications like scarring did not occur within a median follow - up of 13 month. Histopathological evaluation was possible in all cases. CONCLUSION: The UltraCision Harmonic Scalpel offers a surgical treatment of rhinophyma with efficacious intra- and postoperative hemostasis. The combination of simultaneous tissue dissection and hemostasis enables a good overall view and control of the surgical site. Based on its mechanical function, the UltraCision Harmonic Scalpel has only a little thermal effect on neighbouring tissues and a good tactile experience that enables a controlled tissue resection. The UltraCision Harmonic Scalpel combines the advantages of tissue dissection and simultaneous hemostasis with the controlled handling of the traditional scalpel in rhinophyma surgery.

Aged↗

PubMed2003

[Preliminary results for superficial parotidectomy using the ultrasonically activated scalpel (Ultracision Harmonic Scalpel)].

BACKGROUND: The high density of blood vessels in the parotid gland, the direct vicinity to the facial nerve and the narrow surgical situs require efficient intra- and postoperative hemostasis. The ultrasonic scalpel (US) accomplishes both tissue dissection and vessel coagulation simultaneously by an ultrasonically activated shear movement of 55 500 Hz. The combination of hemostasis and tissue dissection particularly qualifies US for use in surgery of the parotid gland. Until now, there have been no published studies about application of US in surgery of the parotid gland. METHOD: 20 patients with benign parotid tumors treated with a conventional technique of superficial parotidectomy and 20 patients with a superficial parotidectomy using the ultrasonically activated scalpel were examined in regard to intra- and postoperative hemostasis, wound healing and postoperative pain. Also, the quality of the histopathological specimen obtained by US was evaluated. RESULTS: In 85 % (17/20) of superficial parotidectomy efficient intraoperative hemostasis did not require electrocoagulation. In 15 % (3/20) of parotid tumors additional bipolar electrocoagulation were required because of venous bleeding from vessels exceeding 2.0 mm in diameter. Postoperative bleeding did not occur at all. Wound healing was uneventful in all cases. Surgery-related postoperative pain was not intensified. Time of operation was shortened. Histopathological evaluation, especially in the margin area, was not impaired. CONCLUSION: The US offers tissue dissection with effective intra- and postoperative hemostasis. The combination of simultaneous tissue dissection and hemostasis enables a good overall view and control of the surgical site. In addition, based on the mechanical function the US has only a minimal thermal effect on neighboring tissues and enables controlled tumor resection without damaging the facial nerve.

Adult↗

PubMed2003

[The valence of dilatational tracheotomy].

After standardizing surgical procedures around 1900 Shelden, Toye, Weinstein and Ciaglia developed the percutaneous dilational tracheotomy (PDT). At present it is recognized that about 50 % of the anesthesiological Intensive care Units (ICU) in Germany are using the PDT while favoring the Ciaglia-technique in the majority of cases. Further techniques are known as Griggs-, Fantoni-, Percu-Twist- and Blue-Rhino-method. Some of these are relatively new, therefore making critical comparison with other methods almost impossible due to lack of experience. The most feared complications of PDT are injury of the cricoid cartilage or of the rear tracheal wall as well as paratracheal positioning of a tracheotomy tube. Comparison between PDT and surgical techniques are difficult due to certain contraindications for PDT which are not valid for surgical procedures. Consecutively PDT will not be able to substitute surgical tracheotomy in the future. It furthermore can't be advocated as an alternative therapeutic option for mobile in-patients outside the ICU.

Bronchoscopy↗

PubMed2003

[Capsular rupture of lymph node metastases as most significant prognostic factor in head and neck squamous cell carcinomas--Hamburg experiences].

BACKGROUND: TNM classification of squamous cell carcinomas of the head and neck contains only size and number of the lymph node metastases. The histological criterion of capsular rupture and its prognostic significance was assessed by an exact histological scheme of capsular rupture and extracapsular spread of the metastasis and was compared with N0 or lymph node metastases without capsular rupture respectively. METHODS: Incidences of distant metastases, tumor recurrences, and survival of 194 consecutive patients with squamous cell carcinomas of the head and neck were investigated. Lymph node metastases were examined by the gradual histological scheme and patients were rated according their histological diagnosis. RESULTS: The classification N0/intranodal tumor growth/extranodal tumor growth resulted in a 5-year survival rate of 74%/62%/25%. According to the classification 67%/72%/37% of the patients were without local recurrent tumor and without distant metastases were 81%/79%/48% after 5 years. CONCLUSIONS: Capsular rupture seems to contain more decisive prognostic value as the criterion of only lymphatic metastatic disease. The histological scheme allows an exact assessment of the capsular rupture or the metastatic pattern of the lymph node. Because of its prognostic significance and individual therapeutic consequences the easily reproducible criterion of capsular rupture is a useful completion to current TNM classification.

Actuarial Analysis↗

PubMed2003

Mechanisms of severe asthma.

The mechanisms behind the development of severe asthma are poorly understood. However, these patients disproportionately consume healthcare resources related to asthma. Severe asthma may develop over time, or may develop shortly after onset of the disease. The genetic and environmental elements that may be most important in the development of severe disease are poorly understood. Physiologically, these patients often have air trapping and airway collapsibility. The pathology demonstrates a heterogeneity of findings, including continued eosinophilic inflammation, an apparently different pathology, structural changes likely to be remodelling related, and predominant distal disease. Treatment remains problematic and likely will remain so until a better understanding of this disease develops.

Allergens↗

PubMed2003

Reverse transcription-polymerase chain reaction assay for species-specific detection of bovine central nervous system tissue in meat and meat products.

This paper reports the development of a reverse transcription-polymerase chain reaction (RT-PCR) assay coupled with restriction fragment length polymorphism (RFLP) analysis to specifically detect the glial fibrillary acidic protein (GFAP) mRNA of bovine central nervous system (CNS) tissue in minced meat and meat products. RNA extracted from bovine brain tissue and brain tissue from other mammals yielded a 168-bp CNS-specific signal after RT-PCR. The species specificity of the assay can be obtained by subsequent RFLP analysis of the amplified RT-PCR product. To determine the tissue specificity of the RT-PCR assay, various bovine tissues were analyzed. Bovine GFAP mRNA was detected in the brain and spinal cord, and these results are consistent with the reported large amounts of detectable protein in these tissues. Additionally, GFAP mRNA was present in skeletal muscle tissue samples and in some heart muscle tissue samples, but heat treatment of samples prior to extraction resulted in the loss of the non-CNS signals. To evaluate the stability and detectability of bovine GFAP mRNA in comminuted meat and in cooked meat products, mixtures containing bovine brain homogenate at concentrations of 0.5 to 5% were prepared and analyzed. The examination of minced meat with added bovine brain homogenate revealedGFAP mRNA RT-PCR signal stability for at least 7 days at a storage temperature of 4 degrees C. In cooked meat products bovine GFAP mRNA signal was detectable for at least 35 days. Bovine brain homogenate at a concentration of 0.5% was successfully detected in all of the experiments conducted, and no false-negative results were obtained. It is concluded that bovine GFAP mRNA can serve as a sensitive and specific marker for bovine CNS tissue in minced meat and in pasteurized meat products.

Animals↗

PubMed2003

Early clinical investigation of Viozan (sibenadet HCl), a novel D2 dopamine receptor, beta2-adrenoceptor agonist for the treatment of chronic obstructive pulmonary disease symptoms.

Viozan, (Sibenadet HCl, AR-C68397AA) is a dual D2 dopamine receptor, beta2-adrenoceptor agonist that combines bronchodilator activity with the sensory afferent modulating effects associated with D2-receptor agonism. Investigation in animal models of key chronic obstructive pulmonary disease (COPD) symptoms has demonstrated that sibenadet effectively inhibits sensory nerve activity, thereby reducing reflex cough, mucus production and tachypnoea. The results of the early clinical evaluation of this novel agent are reported. An initial proof of concept study (Study 1) aimed to determine the clinical potential of this novel agent by assessing the effects of three doses of sibenadet therapy relative to placebo, with two commonly used bronchodilators, intended to provide a benchmark against which sibenadet activity could be judged. In all, 701 patients were randomized to one of three sibenadet dose groups (400, 600 or 1000 microg ex valve), salbutamol 200 microg, ipratropium bromide (IB) 40 microg or placebo, all three times daily via pressurized metered dose inhaler (pMDI) for 4 weeks. Once the results of Study 1 had been evaluated, a dose-ranging, study (Study 2) involving 872 patients randomized to receive sibenadet (45, 270, or 495 microg ex actuator), or placebo all three times daily via pMDI, for 6 weeks commenced. Both studies were preceded by a 2-week baseline phase and followed by a 2-week follow up period.The primary efficacy variable identified changes in key COPD symptoms over the treatment period (compared with baseline data) as determined by the novel Breathlessness, Cough and Sputum Scale (BCSS). In addition, data on lung function, health-related quality of life and adverse events were collected. Patients receiving sibenadet therapy three times daily exhibited statistically significantly greater improvements in BCSS total score than those receiving placebo or bronchodilator therapy alone. A clear dose-response was evident in Study 2. Symptom improvement in this study was also accompanied by improved lung function and health-related quality of life. Sibenadet therapy was well tolerated with an adverse events profile comparable to current bronchodilator therapy. These data were viewed as extremely encouraging, warranting further, large-scale clinical investigation.

Administration, Inhalation↗

PubMed2003

[New aspects of the mechanics of the auditory tube].

The aim of the present article is to describe the mechanical components of the auditory tube and the role of these components in auditory tube function. Particular attention will be given to those aspects which have not been sufficiently dealt with in the past, such as the role of the isthmus region, the function of the lateral mucosal folds, the significance of the of the surfactant proteins and the pathophysiology of the patulous auditory tube. Special attention is given to the tensor veli palatini muscle and its physiology. Because of its isometric contraction, the function of this muscle depends on so-called hypomochlia changing the direction of its force. In the context of this article, the three hypomochlia involved are the pterygoid hamulus, Ostmann's fatty tissue and the medial pterygoid muscle. The so-called "Eppendorf-maneuver" is depicted for the first time.

Biomechanical Phenomena↗

PubMed2002

[Reducing late toxicity with amifostine in fractionated irradiation of the rat salivary glands].

Clinical studies show that amifostine can reduce xerostomia and mucositis during radiotherapy of head and neck cancers. The aim of this study was to evaluate the radioprotective potency of amifostine with respect to late toxicity of salivary glands of rats. The head-neck-area of 8 male WAG/RijH rats (295 +/- 7 g) were irradiated with 60Co-gamma-rays (60 Gy/30 f/6 weeks). Amifostine (250 mg/m2 body surface) was applied via a venous port 15 min before each irradiation. Rats of a control group were irradiated with the same schedule with equal volumes of physiological saline. The morphological and sialoscintigraphical findings clearly demonstrate that amifostine has a remarkable cytoprotective effect on the late toxicity of irradiated salivary glands.

Amifostine↗

PubMed2002

[The "Ultracision Harmonic Scalpel" ultrasound activated scalpel. Initial results in surgery of the tongue and soft palate].

The ultrasonically activated scalpel (UAS) performs tissue dissection and coagulation simultaneously by an ultra-high-frequency movement of the blade. In the present prospective study, results of UAS in the surgery of the tongue and the soft palate are analysed. 25 patients with carcinoma of the tongue and 11 patients with carcinoma of the soft palate were examined in regard to intra- and postoperative hemostasis, wound healing and postoperative pain. Also, the quality of the histo-pathological specimen obtained by UAS was evaluated. In 68% (17/25) of partial tongue resections, and in 82% (9/11) of soft palate resections efficient intraoperative hemostasis did not require electrocoagulation or suture ligature. In 32% (8/25) of tongue malignancies, all with extension to the tongue base, and in 18% (2/11) of soft palate resections additional ligation was required because of arterial bleeding from vessels exceeding 1.0 mm in diameter. Wound healing was uneventful in all cases. The histopathological evaluation, especially in the margin area, was not impaired. The UAS offers a tissue dissection with efficacious intra- and postoperative hemostasis. Arterial bleeding from vessels exceeding 1.0 mm in diameter should be sutured additionally. The combination of simultaneous tissue dissection and hemostasis enables a good overall view and control of the surgical situs. In addition, based on the mechanical function the UAS has only little thermical effect on neighbouring tissues and enables a controlled tumor resection without damaging vital structures.

Adult↗

PubMed2002

[Radioprotective effectiveness of amifostine on the salivary glands of the rat during fractionated irradiation].

BACKGROUND: The aim of this study was to evaluate the cytoprotective potency of amifostine during a fractioned irradiation of salivary glands but also on the tumor response of rhabdomyosarcomas R1H in rats. METHOD: The head-neck-area of male WAG/RijH rats and the tumor in the flank were irradiated with 60Co-gamma-rays (60 Gy/30 f/6 weeks). Amifostine (250 mg/m2) was applicated 15 min before irradiation. The control group was treated with an equal volume of physiologic sodium chloride. The salivary glands were exstirpated and examined histopathologically. Tumour volume was measured, the body-weight of rats determined. RESULTS: A dose dependent radiosialadenitis developed in all salivary glands. Amifostine had no influence on the response of R1H tumours to radiation. The animal weight loss in the amifostine group was higher as compared to control group. CONCLUSIONS: No cytoprotective effects on acute toxicity of salivary glands of rats could be detected under irradiation with synchronous application of amifostine. In addition, no effects on tumor response were observed. The general animal constitution decreased by additional medication of amifostine.

Amifostine↗

PubMed2001

Redox-sensitive intermediates mediate angiotensin II-induced p38 MAP kinase activation, AP-1 binding activity, and TGF-beta expression in adult ventricular cardiomyocytes.

Cardiac hypertrophy as an adaptation to increased blood pressure leads to an increase in ventricular expression of transforming growth factor Cardiac hypertrophy as an adaptation to increased blood pressure leads to an increase in ventricular expression of transforming growth factor b (TGF-b), probably via the renin-angiotensin system. We studied in vivo to determine whether angiotensin II affects TGF-b expression independent from mechanical effects caused by the concomitant increase in blood pressure and in vitro intracellular signaling involved in angiotensin II-dependent TGF-b1 induction. In vivo, the AT1 receptor antagonist losartan, but not reduction of blood pressure by hydralazine, inhibited the increase in TGF-b1 expression caused by angiotensin II. In vitro, angiotensin II caused an induction of TGF-b1 expression in adult ventricular cardiomyocytes and induced AP-1 binding activity. Transfection with "decoys" directed against the binding site of AP-1 binding proteins inhibited the angiotensin II-dependent TGF-b induction. Angiotensin II induced TGF-b expression in a p38-MAP kinase-dependent way. p38-MAP kinase activation was diminished in presence of the antioxidants or diphenyleneiodium chloride, or by pretreatment with antisense nucleotides directed against phox22 and nox, components of smooth muscle type NAD(P)H oxidase. Thus, our study identifies a previously unrecognized coupling of cardiac AT receptors to a NAD(P)H oxidase complex similar to that expressed in smooth muscle cells and identifies p38-MAP kinase activation as an important downstream target.

Angiotensin II↗

PubMed2001

TGF-beta(1) downregulates PTHrP in coronary endothelial cells.

Parathyroid hormone-related peptide (PTHrP) is expressed throughout the cardiovascular system including coronary endothelial cells. Factors involved in the regulation of cardiac PTHrP expression have not been examined before. This study investigates the influence of transforming growth factor (TGF)-beta(1)on ventricular PTHrP expression. Coronary endothelial cells were isolated from ventricles of adult rats and PTHrP protein expression in these cultures was analysed by immunoblotting. TGF-beta(1)caused a concentration-dependent reduction in PTHrP protein within 24 h. In transgenic mice over-expressing TGF-beta(1)ventricular PTHrP protein expression and release was reduced compared to non-transgenic littermates. Similar concerns hold for PTHrP mRNA content (RT-PCR). Since ventricular TGF-beta(1)expression increases under pathophysiological conditions like arterial hypertension, ventricular PTHrP expression was further determined in aging spontaneously hypertensive (SHR-SP) and normotensive rats. TGF- beta(1)expression was increased in SHR-SP and ventricular PTHrP mRNA expression was downregulated at the age of 10 months. PTHrP expression did not recover in elder SHR-SP in which TGF-beta(1)expression was normalized again. Finally, we investigated ventricular PTHrP expression in rats after banding of the ascending aorta which generates a pressure induced hypertrophy without an induction of TGF-beta(1)expression. In ventricles from these animals, PTHrP expression was transiently increased and normalized at day 3. In conclusion, PTHrP expression was reduced under all conditions in which coronary endothelial cells were exposed to TGF-beta(1). PTHrP expression does not correlate with cardiac hypertrophy. Since coronary endothelial cells represent the majority of PTHrP producing cells in the ventricle its downregulation by TGF- beta(1)seems to be relevant for the paracrine effects of PTHrP.

Aging↗

PubMed2001

[Tonsillectomy with the ultrasound activated scalpel. Initial results of technique with Ultracision Harmonic Scalpel].

BACKGROUND: Tonsillectomy requires an efficient intra- and postoperative hemostasis. The ultrasonically activated scalpel (UAS) uses high-frequency ultrasonic energy to perform tissue dissection and coagulation simultaneously. The present prospective study represents the first published results of UAS in tonsillectomy. METHOD: 60 patients with tonsillectomy were examined in regard of intra- and postoperative hemostasis, wound healing and postoperative pain. Also, the quality of the histopathological specimen was evaluated. RESULTS: In 90% of tonsillectomies by UAS efficient intraoperative hemostasis did not require suture ligature. In 10% additional ligation was required for reason of arterial bleeding. Postoperative bleeding did not occur at all, wound healing was uneventful. Surgery related postoperative pain was not intensified. The histopathological evaluation of specimen was not impaired. CONCLUSION: The UAS offers a tissue dissection with efficacious intra- and postoperative hemostasis. Compared to the conventional tonsillectomy the ultrasonical technique of tonsillectomy has especially in children, in anaemic patients and in the surgery of tonsillar malignomas significant advantages.

Adolescent↗

PubMed2001

[Cutaneous malignant melanoma in the area of the head and neck with intermediate tumor thickness: does primary site have prognostic relevance?].

BACKGROUND: Tumor thickness and infiltration of malignant melanoma are the main prognostic factors for recurrence and survival. The sentinel lymph node biopsy may provide a step toward a more individual staging and therapy. It was the aim of this study to investigate the prognostic influence of the primary localization of head and neck melanoma subdivided into scalp, ear, neck, and face. To form a basis for routine sentinel lymph node biopsy in case of intermediate tumor thickness metastatic pattern of the different primary sites were analysed. METHOD: Survival rates depending on primary tumor site of 51 patients with cutaneous malignant melanoma of the head and neck were analysed. Metastatic pattern were evaluated with the help of clinical, intraoperative, pathohistologic data. RESULTS: Scalp and ear melanoma were found to be higher risk lesions with a 5-year survival rate of 28% and 59% respectively. Melanoma of the neck and face had a 5-year survival rate of 75% and 78% respectively. In two cases of ear melanoma lymph node metastases could be demonstrated in unusual sites by skipping the first draining basin. In three cases bilateral metastases could be shown histologically as opposed to clinical prediction. CONCLUSIONS: Localization of cutaneous malignant melanoma of the head and neck is a prognostic factor for survival. Because of the discordancy between clinical prediction and lymphatic drainage pattern sentinel lymph node biopsy improves accuracy of diagnostic and therapeutic procedures.

Follow-Up Studies↗

PubMed2001

[Comparison between the Eppendorf histograph and the Licox system for determination oxygen partial pressure in tumor tissue].

BACKGROUND: The oxygenation of a tumor is certainly one of the major facts influencing the response to treatment. pO2 measurement in tumor tissue can be done by using the Eppendorf-histograph. In recent years the Licox-system (GMS) was developed for oxygen tension measurement in tissues and fluids under clinical routine conditions and for research work. Aim of the present study was to assess the suitability of the Licox-system in drawing up histograms of pO2 values in tumor tissues. METHOD: Histograms of the distribution of oxygen tension in twelve tumors were prepared with both measuring systems in parallel. Investigations were performed on rats with isotransplanted R1H rhabdomyosarcomas in continuous intravenous anesthesia with Fentanyl and Dormicum. Ventilation with a mixture of air and oxygen was applied through a tracheostoma. Arterial pressure and body temperature were analysed and balanced continuously. RESULTS: No correspondence between data of both measuring methods could be found. CONCLUSIONS: Because of constructional advantages the Eppendorf-histograph seems to be comparatively more suitable in drawing up histograms of oxygen tension tumor tissue.

Animals↗

PubMed2001

Tetracycline residues in meat and bone meals. Part 2: the effect of heat treatments on bound tetracycline residues.

The stability of bound tetracycline residues during heat treatments at 133 degrees C and 100 degrees C for up to 45 min was investigated. An intermediate product from a rendering plant was mixed with bone splinters that contained bound tetracycline (TC) and chlortetracycline (CTC) residues. The mixture was heated in an autoclave at 133 degrees C for 20, 30 and 45 min and at 100 degrees C for 20 and 30 min and subsequently dried at 103 degrees C for 4 h. Two different extraction procedures with hydrochloric acid were used, one with and one without the previous sedimentation of bone particles. Tetracycline concentrations were determined by HPLC analysis before and after the heat treatment. A complete destruction of tetracyclines during heat treatment at 133 degrees C could not be demonstrated, but there was a significant decrease of TC by about 50%. CTC was less resistant to the same temperature, which brought about a reduction of 90-100%. Treatment at 100 degrees C did not bring about any reduction, except for CTC after extraction without sedimentation. The possible toxicological relevance of the findings is discussed. Further research has to be done on possible degradation products of the tetracycline derivatives.

Animals↗