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Biomedical subjects

G Friedrich

Publications and source records attributed to G Friedrich.

At least 19 recordsLinked to original sources
PubMed2002

[Development of a jet tracheoscope. Value and possible uses in superimposed high frequency jet ventilation in endoscopic surgery of the respiratory tract].

BACKGROUND AND OBJECTIVE: Tubeless jet-ventilation offers the surgeon an unimpaired surgical field and is therefore widely used in endolaryngeal surgery. In order to permit endotracheal surgery using the same devices and instruments as those used for the larynx, we have developed special jet-tracheoscopes. Here, we report on our experience with superimposed high-frequency jet-ventilation (SHFJV) together with total intravenous anaesthesia (TIVA) in endolaryngeal and especially endotracheal surgery. PATIENTS AND METHODS: The medical reports of 172 patients (91 females, 81 males) who had undergone endolaryngeal or endotracheal surgery in SHFJV were analysed retrospectively. RESULTS: Sufficient ventilation was possible in all cases and no vitally critical situation occurred. The main indication was laryngotracheal stenosis of different origins. No significant advantages could be observed in phonosurgery. There was no difficulty in exposing the endolarynx and subglottis with the currently available laryngoscopes (five sizes). The newly developed jet-tracheoscopes (two sizes) allowed a quick and safe extension of the operating field onto the tracheal bifurcation. CONCLUSIONS: SHFJV together with TIVA enlarges the diagnostic and therapeutic options in endoscopic surgery of the respiratory tract and is in many cases the precondition for endoscopic treatment without tracheotomy. In particular, the newly developed jet-tracheoscopes widen the spectrum of endoscopic surgery and allow the use of the micromanipulator guided CO2-laser in the trachea.

Adolescent↗
PubMed2001

Optical dysfunction of the crystalline lens in aquaporin-0-deficient mice.

Aquaporin-0 (AQP0), a water transport channel protein, is the major intrinsic protein (MIP) of lens fiber cell plasma membranes. Mice deficient in the gene for AQP0 (Aqp0, Mip) were generated from a library of gene trap embryo stem cells. Sequence analysis showed that the gene trap vector had inserted into the first exon of Aqp0, causing a null mutation as verified by RNA blotting and immunochemistry. At 3 wk of age (postnatal day 21), lenses from null mice (Aqp0(-/-)) contained polymorphic opacities, whereas lenses from heterozygous mice (Aqp0(+/-)) were transparent and did not develop frank opacities until approximately 24 wk of age. Osmotic water permeability values for Aqp0(+/-) and Aqp0(-/-) lenses were reduced to approximately 46% and approximately 20% of wild-type values, respectively, and the focusing power of Aqp0(+/-) lenses was significantly lower than that of wild type. These findings show that heterozygous loss of AQP0 is sufficient to trigger cataractogenesis in mice and suggest that this MIP is required for optimal focusing of the crystalline lens.

Age Factors↗
PubMed2001

[Pressure distribution measurements during use of wheelchairs].

There is a growing number of mobility-impaired and wheelchair-dependent patients caused by diseases and injuries of the central nervous system. The risk is high for pressure sores to develop due to disturbances of the motor, sensory, and autonomic nervous system. Numerous seating systems for prophylaxis and treatment of decubitus ulcer are available. To identify risk parameters, the literature on animal experiments regarding pressure ulcers was reviewed. A study on the reproducibility of the analysis method with capacitive sensors tested in ten paraplegics with 470 measurements is presented. It shows the reliability of the procedure.

Biomechanical Phenomena↗
PubMed2001

A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Guideline elaborated by the Committee on Phoniatrics of the European Laryngological Society (ELS).

The proposal of this basic protocol is an attempt to reach better agreement and uniformity concerning the methodology for functional assessment of pathologic voices. The purpose is to allow relevant comparisons with the literature when presenting/publishing the results of voice treatment, e.g. a phonosurgical technique, or a new/improved instrument or procedure for investigating the pathological voice. Meta-analyses of the results of voice treatments are generally limited and may even be impossible owing to the major diversity in the ways functional outcomes are assessed. A multidimensional set of minimal basic measurements suitable for all "common" dysphonias is proposed. It includes five different approaches: perception (grade, roughness, breathiness), videostroboscopy (closure, regularity, mucosal wave and symmetry), acoustics (jitter, shimmer, Fo-range and softest intensity), aerodynamics (phonation quotient), and subjective rating by the patient. The protocol is elaborated on the basis of an exhaustive review of the literature, of the experience of the Committee members, and of plenary discussions within the European Laryngological Society. Instrumentation is kept to a minimum, but it is considered essential for professionals performing phonosurgery.

Clinical Protocols↗
PubMed2001

Laryngeal framework surgery: a proposal for classification and nomenclature by the Phonosurgery Committee of the European Laryngological Society.

Laryngeal framework surgery, developed by Isshiki in the 1970s, is one of the most dynamic areas of phonosurgery and these procedures have served to considerably widen our spectrum and options for surgical improvement and/or changing of voice. As these techniques became more accepted and became common throughout the world, several new surgical modifications and different terms have been introduced. These new developments have lead to a confusion regarding terminology and types which make it difficult to communicate between and to compare the results of different authors. In an effort to create a more precise and descriptive list of definitions and terms, the Phonosurgery Committee of the European Laryngological Society has developed a new terminology for laryngeal framework surgery. In accordance with the concept of Isshiki, four types can be separated according to the intended purpose of the surgery: -Approximation laryngoplasty: medialization thyroplasty, arytenoid adduction. -Expansion laryngoplasty: lateralization thyroplasty, vocal fold abduction. -Relaxation laryngoplasty: shortening thyroplasty -Tensioning laryngoplasty: cricothyroid approximation, elongation thyroplasty. The proposed terms are functionally oriented and related closely to the intended purpose of the procedure or related to the underlying pathogenesis of the dysphonia. This new classification should provide a general framework suited not only to classify the current techniques but also to easily apply and adapt to include new procedures and future developments as necessary.

Humans↗
PubMed2001

Laryngeal manifestation of gout: a case report of a subglottic gout tophus.

A subglottic tophaceous deposition of urate crystals is a rare finding. We report on a case of a male Caucasian who had a moderate dysphonia without any further laryngeal symptoms. The laryngoscopy revealed a hemispheric lesion on the left subglottic region. An excision biopsy was performed, and the histopathological examination of the dissected specimen showed a tophus. Diagnostic and therapeutic strategies are discussed.

Arytenoid Cartilage↗
PubMed2001

Carcinoma of the larynx: predictors of diagnostic delay.

OBJECTIVES: In tumors of the upper aerodigestive tract a dose-response relationship between tumor stage and its prognosis raises the chance of a reduction in the diagnostic delay. The interval between the first symptom and the start of tumor-specific therapy and the influencing factors is not well known. The goals of this study were to investigate the diagnostic delay and the influencing factors and to predict the factors that prolong the diagnostic process. STUDY DESIGN: Prospective, nonrandomized study. METHODS: The intervals between first symptom and first consultation of a physician (patient delay) and between first consultation and first tumor-specific therapy (doctor delay) were investigated. Predictors for increased patient or doctor delay were evaluated, and a multiple logistic regression model for increased doctor delay was developed. RESULTS: The total diagnostic delay (sum of patient and doctor delays) was 3 to 4 months. A multifactorial model for the ratio of odds revealed that for women and glottic cancers (1.73) the chance was twice as high for a doctor delay greater than 30 days, whereas subjects with an increased patient delay (>30 d) had reduced odds of being delayed by the physician. CONCLUSIONS: The higher chance of extended doctor delay for glottic tumors compared with supraglottic tumors should be reflected in differential therapeutic strategies. Even unspecific lesions of the vocal folds should be followed up at the end of the therapy, at least. Therapies of glottic lesions without final control have the chance of resulting in delays in treatment. Women, especially, should be included in a follow-up examination. On the other hand, patients with increased patient delay have lower odds of longer doctor delay, which may be the result of tumor growth and, consequently, easier diagnosis.

Carcinoma, Squamous Cell↗
PubMed2000

Hypernasality--a rare initial symptom of a cerebellar astrocytoma.

Nasality is a disorder due to nasal resonance, which may be induced by a variety of etiologies. Transitional hypernasality is frequently seen in children after adenoidectomy. The alleged post-surgical hypernasality in the case presented was shown to be related to the late detection of an astrocytoma of the cerebellum and the brain stem in a 6-year-old boy. This case was characterized by increased hypernasality which failed speech therapy. A developing one-sided vocal fold palsy in combination with an ipsilateral soft-palate palsy indicated further investigation. Computerized tomography (CT) and magnetic resonance imaging (MRI) revealed a brain stem-tumor with a maximum size of 6 cm involving parts of the cerebellum. These findings demonstrated the need for a strict follow-up, even after adenoidectomy, in the presence of hypernasality for identifying concurrent etiologies as well as cases suitable for speech therapy.

Adenoidectomy↗
PubMed2000

Structure of the cytoplasmic domain of p23 in solution: implications for the formation of COPI vesicles.

Coatomer, the coat protein complex of coat protein (COPI) vesicles, is involved in the budding of these vesicles. Its interaction with the cytoplasmic domains of some p24-family members, type I transmembrane proteins of the Golgi, has been shown to induce a conformational change of coatomer that initiates polymerization of the complex. From stoichiometrical data it is likely that interaction of coatomer with the small tail domains involves an oligomeric form of the p24 proteins. Here we present the structure of peptide analogs of the cytoplasmic domain of p23, a member of the p24 family, as determined by two-dimensional nuclear magnetic resonance spectroscopy in the presence of 2,2,2-trifluoroethanol. An improved strategy for structure calculation revealed that the tail domain peptides form alpha-helices and adopt a tetrameric state. Based on these results we propose an initial model for the binding of coatomer by p23 and the induced conformational change of coatomer that results in its polymerization, curvature of the Golgi membrane to form a bud, and finally a COPI-coated vesicle.

Amino Acid Sequence↗
PubMed2000

Endoscopic cordectomy. A proposal for a classification by the Working Committee, European Laryngological Society.

The European Laryngological Society is proposing a classification of different laryngeal endoscopic cordectomies in order to ensure better definitions of post-operative results. We chose to keep the word "cordectomy" even for partial resections because it is the term most often used in the surgical literature. The classification comprises eight types of cordectomies: a subepithelial cordectomy (type I), which is resection of the epithelium; a subligamental cordectomy (type II), which is a resection of the epithelium, Reinke's space and vocal ligament; transmuscular cordectomy (type III), which proceeds through the vocalis muscle; total cordectomy (type IV); extended cordectomy, which encompasses the contralateral vocal fold and the anterior commissure (type Va); extended cordectomy, which includes the arytenoid (type Vb); extended cordectomy, which encompasses the subglottis (type Vc); and extended cordectomy, which includes the ventricle (type Vd). Indications for performing those cordectomies may vary from surgeon to surgeon. The operations are classified according to the surgical approach used and the degree of resection in order to facilitate use of the classification in daily practice. Each surgical procedure ensures that a specimen is available for histopathological examination.

Glottis↗
PubMed2000

Atrial natriuretic factor (ANF) after laparoscopy and morphine application for pain therapy.

OBJECTIVE: ANF is a potent diuretic, natriuretic and vasorelaxant hormone. The objective of the present study was to examine the effect of opioid receptor stimulation by morphine on endogenous ANF production and diuresis after surgery. METHODS: Prospectively, nine women undergoing surgery for either uterine leiomyomas, chronic pelvic discomfort or desire for definitive contraception by laparoscopy were evaluated. Venous samples were collected at fixed times. Concentrations of ANF were measured by commercially available radioimmunassay test kits. Statistical analysis was performed by the Friedman Two-way ANOVA, Kruskal-Wallis 1-way ANOVA and Mann-Whitney U-Wilcoxon Rank Sum W Test. The level of significance was set at a probability below 0.05. RESULTS: There were no statistically significant changes in serum levels of ANF (p = 0.98), in diastolic blood pressure (p = 0.14) or pain score (p = 0.86) after surgery. Systolic blood pressure (p = 0.0032), pulse rate (p = 0.019) and urinary flow rate (p < 0.0001) showed significant changes during observation. CONCLUSION: Our results show that i.v. administered morphine induces a potent diuretic effect via activation of opioid receptors but it can not be suggested that this effect is due to an enhanced release of ANF.

Adult↗
PubMed2000

Evaluation of the secretion of the atrial natriuretic factor (ANF) after laparotomy.

BACKGROUND: ANF is a potent diuretic, natriuretic and vasorelaxant hormone. The objective of the present study was to examine the effect of opioid receptor stimulation by morphine after surgery on endogenous ANF production and diuresis. METHODS: Prospectively, 11 women undergoing surgery for either uterine leiomyomas, chronic pelvic discomfort or desire for definitive contraception by laparotomy were evaluated. Venous samples were collected at fixed times. Concentrations of ANF were measured by commercially available radioimmunoassay test kits. Statistical analysis was performed by the Friedman Two way ANOVA. Kruskal-Wallis 1-way ANOVA and Mann-Whitney U-Wilcoxon Rank Sum W Test. The level of significance was set at probability below 0.05. RESULTS: There were statistically significant changes in the serum levels of ANF (p=0.0028), in pain score (p<0.0001) and urinary flow rate (p<0.0001) after operation, while the diastolic (p=0.0671) and systolic (p=0.0543) blood pressure showed slightly significant changes. CONCLUSION: Our results show that i.v. administered morphine induces a potent diuretic effect via activation of opioid receptors and suggest that this effect is due to the enhanced release of ANF. However the mechanism by which morphine induces the ANF release remains to be evaluated.

Adult↗
PubMed1999

Life-threatening tracheal metastasis complicating ovarian cancer--a case report.

BACKGROUND: Tracheal metastasis is a rare manifestation of recurrent ovarian cancer. CASE: We describe tracheal metastasis causing increasing respiratory distress in a patient with progressive stage IIIc undifferentiated serous-papillary cancer involving the peritoneum and pleura and the retroperitoneal, diaphragmatic, parahilar, mediastinal, pretracheal, paratracheal, and supraclavicular lymph nodes. The situation necessitated rapid endoscopic laser ablation. CONCLUSION: Malignant tracheal obstruction should be considered in the differential diagnosis of patients with advanced ovarian cancer and respiratory distress.

Adult↗
PubMed1999

Ex juvantibus approach for chronic posterior laryngitis: results of short-term pantoprazole therapy.

The aim of this study was to investigate whether patients with chronic posterior laryngitis and symptoms of gastro-pharyngeal reflux benefit from a six-week therapy with pantoprozole. Twenty-nine out-patients with voice disorders (case history of at least two months) and simultaneous symptoms of gastro-pharyngeal reflux were recruited for this study. At the entry to the study a symptom questionnaire and a video-laryngo/stroboscopy were completed. The symptom questionnaire and the video-laryngo/stroboscopy were repeated after the six weeks of therapy with pantoprazole 40 mg once a day and again six weeks and three months after this follow-up, during which time the patient was without therapy. Hoarseness, globus pharyngeus, sore throat, heartburn, and coughing were the symptoms which showed a significant (p < 0.05) recovery at the follow-ups (mean of hoarseness index: 7.28 to 0.92; mean of globus pharyngeus index: 3.14 to 0.58; mean of heartburn index: 2.86 to 0.5; mean of cough index: 1.72 to 0.25; mean of throat soreness index: 1.72 to 0.15). Laryngoscopy scores of the posterior laryngeal region, the glottic and the supraglottic region showed statistically significant improvement (p < 0.05) after the treatment with pantoprazole. The therapeutic effect exceeded the drug administration until the last follow-up (after three months). The medication was tolerated without side-effects in all patients. A primary (ex juvantibus) therapy with proton pump inhibitors seems to be a therapeutic option for patients with long-lasting chronic inflammation of the larynx not responding to common therapy. In this case a six-week course of treatment has been shown to be sufficient.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1999

Giant liposarcoma of the esophagus: radiological findings.

This case of an esophageal liposarcoma illustrates a polypoid lesion within the esophagus that extended from the left pyriform sinus to the distal esophagus above the gastric cardia. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) showed an inhomogenously-enhancing intraluminal mass, while video-fluoroscopy revealed that the mass was adherent to the esophageal wall and was associated with esophageal dilatation and diminished peristalsis. This ninth reported case of esophageal liposarcoma is the first described where preoperative radiologic studies and endoscopy showed broad fixation of the tumor to the esophageal wall.

Aged↗
PubMed1999

Titanium vocal fold medializing implant: introducing a novel implant system for external vocal fold medialization.

With the increasing worldwide spread of the Isshiki technique for external vocal fold medialization, some disadvantages and limitations have also emerged. and an increasing demand for a ready-made and standardized implant system can be observed. For this reason. I started experimental and clinical investigations with the goal of replacing the silicone with a safer material, and also simplifying and standardizing the surgical procedure. In particular, the danger of implant dislocation should be excluded with greater certainty. As a result, I have developed an implant made of medical-grade titanium. My surgical experiences in 20 patients with this newly developed titanium vocal fold medializing implant revealed that vocal fold medialization could be performed easily and that no perioperative complications occurred in any case. The major advantage was a significant reduction of operative time due to the preformed implant. This is not only more convenient for both the surgeon and the patient, but is also critical for obtaining optimal results due to the reduced intralaryngeal swelling and hematoma. The reduction of the glottic gap by the operation was statistically significant. Significant improvement of all voice parameters was achieved and demonstrated by a statistically significant reduction of the voice dysfunction index. Compared to the current techniques and implant systems, I see the following additional advantages: 1) titanium is a relatively safe implant material with excellent biocompatibility: 2) the design of the implant ensures optimal fixation and stabilization: 3) the implantation technique and handling is simple and time-saving; 4) the titanium sheet is easy to shape and adapt to the individual situation: and 5) only 2 sizes of implants, and no expensive instruments, are required.

Adult↗