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Biomedical subjects

F Waldfahrer

Publications and source records attributed to F Waldfahrer.

26 records · Page 2Linked to original sources
PubMed1996

In vitro effects of high-energy pulsed ultrasound on human squamous cell carcinoma cells.

Human squamous cell carcinoma cells cloned from the hypopharynx (FaDu) and oral cavity (SCC-4) were exposed to high-energy pulsed ultrasound (HEPUS) in vitro to evaluate the effects of various physical parameters on cell viability. Such included the number of pulses, voltage applied, pulse repetition rate and cell density. The experimental piezoelectric ultrasound transducer used in the experiments generated pulses with a high negative pressure amplitude. By varying the repetition frequency from 0.6 to 8 Hz, cell viability was found to be least when pulse repetition was approximately 1 Hz. An increase in transducer voltage resulted in a linear decrease in cell viability. The cell survival rate dropped exponentially as a function of the number of pulses applied, reaching 4.2% after 2000 pulses. The cell survival rate exhibited no significant dependence on cell density when cells ranged from 1 to 3.5 x 10(6) cells ml-1. Data obtained with trypan blue dye exclusion were confirmed by measurements of intracellular lactate dehydrogenase released into an extracellular fluid supernatant. By applying HEPUS to tumor cells, almost complete destruction of the cells could be achieved in vitro. The degree of cell destruction achieved depended significantly on the number of pulses administered, the pulse repetition rate and the transducer voltage applied.

Carcinoma, Squamous Cell↗
PubMed1996

[Current status of minimally invasive treatment methods in sialolithiasis].

Newly available minimally invasive methods have changed established treatment of human sialolithiasis during the past several years. After basic in vitro and in vivo investigations, two systems of shockwave treatment proved to be useful for clinical application: extracorporeal shockwave lithotripsy (piezoelectric system) and intracorporeal laser lithotripsy (using a rhodamine-6G dye laser). Following our clinical experiences with these methods a differential scheme for managing sialolithiasis is recommended depending on localization of the calculi and their maximal diameters. Submandibular stones are best treated by extra-corporeal lithotripsy if the stone is located in intraglandular parts or in the gland hilum. Stones of the hilum can also be treated by laser lithotripsy. In the distal parts and near the duct orifice, papillotomy and stone extraction should be tried independent of the stone size. If the stone is located in the intraglandular parts of the duct system or in the hilum and its diameter is over 12 mm, submandibulectomy is necessary. Calculi of the parotid gland should only be treated by extracorporeal lithotripsy, regardless of size and location.

Endoscopes↗
PubMed1995

[Asbestos dust-induced laryngeal carcinoma--a new occupational disease? Current scientific knowledge and social health regulations].

According to the current regulations pertaining to occupational diseases lung cancer and mesothelioma can be compensated as asbestos-related malignomas under certain circumstances. For several years there has been controversial discussion as to whether laryngeal carcinomas can also be caused by occupational asbestos exposure and should therefore be added to the list of occupational diseases. Critical evaluation of the available scientific knowledge with the scope of currently applicable regulations does not warrant adding asbestos-related laryngeal carcinomas to the list of occupational diseases at present. Further investigations are urgently necessary and may possibly bring new insights.

Aged↗
PubMed1995

[Severe oropharyngeal angioedema caused by ACE inhibitor. A case report].

Inhibitors of angiotensin converting enzyme (ACE) are suspected of inducing angioedemas in up to 0.2% of all patients. These angioedemas are mainly localized in the upper airways and therefore can cause severe airway obstruction and even death due to suffocation. We report the case of a 64-year-old man, who underwent emergency tracheotomy because of severe angioedema of the larynx, which was refractory to pharmacological treatment. We conclude that patients with ACE inhibitor-induced angioedemas should be observed by monitoring in an intensive care unit to ensure the possibility of early intubation, because conventional antiallergic-antiedematous therapy by histamine-receptor antagonists and corticosteroids is an insufficient, unreliable form of therapy in severe cases. Especially otolaryngologists should know about this uncommon potentially life-threatening side-effect of ACE inhibitors.

Angioedema↗