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Biomedical subjects

G Friedrich

Publications and source records attributed to G Friedrich.

At least 19 recordsLinked to original sources
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

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↗
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↗
PubMed1999

Evaluation of stress-related hormones after surgery.

INTRODUCTION: Improvements in instrumentation, optics, video cameras and technology have brought laparoscopy to the point at which many surgical procedures that once could be performed only by laparotomy are now successfully performed endoscopically. PATIENTS AND METHOD: Twenty women undergoing surgery by laparotomy (11 patients) or laparoscopy (9 patients) were evaluated prospectively. Concentrations of adrenaline, noradrenaline, cortisol, prolactin, and ACTH were measured. Statistical analysis was performed by using the Friedman Two-way ANOVA, Kruskal-Wallis 1-way ANOVA and Mann-Whitney U-Wilcoxon Rank Sum W Test. RESULTS: By comparing the means of all serum levels of ACTH, cortisol and prolactin between the laparoscopy and the laparotomy group, significant differences of ACTH (p < 0.0001), prolactin (p = 0.0164) and cortisol (p < 0.0001) were found. Furthermore, statistically significant differences (p < 0.05) of the serum levels of noradrenaline and adrenaline between the laparoscopy and the laparotomy group were observed. DISCUSSION: While laparoscopic surgery causes less activation of stress-related hormones laparotomy results in a much more obvious response to all hormones evaluated, particularly catecholamine and ACTH production. This is probably related to the major tissue trauma.

Adrenocorticotropic Hormone↗
PubMed1998

Single coronary artery bypass grafting--a comparison between minimally invasive 'off pump' techniques and conventional procedures.

OBJECTIVE: At present, few studies directly comparing minimally invasive and conventional coronary artery bypass grafting are available. The aim of the present study was to evaluate the clinical outcome of the two techniques. METHODS: We retrospectively compared our first consecutive 20 patients undergoing minimally invasive coronary artery single bypass grafting on the beating heart (group I) with 23 consecutive patients receiving single coronary artery bypass via sternotomy using cardiopulmonary bypass and cardioplegia (group II). The procedures were performed during the period from Jan 1, 1994 to Feb 20, 1997. There were no significant differences in demographic data. RESULTS: Statistically significant differences were found concerning total operative time (172.6 min in group I and 149.6 min in group II P = 0.0009) and myocardial ischemic time (23.7 min local coronary occlusion time in group I and 17.6 min aortic cross-clamp time in group II P = 0.03. Patients treated minimally invasive received significantly fewer blood transfusions (25.0% vs. 69.6% P = 0.0035) and were discharged significantly earlier from the hospital (admission rate on the fifth postoperative day 68.4% in group I vs. 100.0% in group II P = 0.0004). CONCLUSION: We conclude that minimally invasive coronary artery bypass grafting on the beating heart in comparison to conventional single coronary artery bypass grafting during the learning curve requires longer operative times but can reduce blood transfusion requirements and hospital stay.

Blood Transfusion↗
PubMed1998

[External vocal fold medialization: surgical experiences and modifications].

BACKGROUND: Despite a first report as early as 1915 by Payr, vocal fold medialization by an external approach did not gain general acceptance for many decades. Only when Isshiki took up these first attempts again in the 1970s, fundamentally revised them, and expanded the methods into the groups of Laryngeal Framework Surgery and Thyroplasty, did these techniques spread. Now they are increasingly performed. We have been using this technique since 1991. In a retrospective study we critically reviewed surgical experience with the original technique and several newly developed surgical modifications. PATIENTS: An external vocal fold medialization was performed in 53 patients (22 male, 31 female). The underlying cause for the glottic insufficiency was in most of the cases unilateral laryngeal palsy, predominantly caused by thyroid surgery. Ten patients presented with an atrophy and/or scar of the vocal folds. In 7 out of these 10 cases the vocal folds were mobile. Most of the patients were operated on (n = 32) using the Isshiki technique. In the remaining 21 patients surgical modifications were used. In 7 cases new developed implants made out of glass ionomer cement were used, in 5 patients vocal fold medialization was performed using a 0.25 mm titanium sheet. RESULTS: No intraoperative or postoperative complications could be observed. The surgical procedure was very well tolerated by all patients. The degree of glottic insufficiency was significantly reduced. There was also a statistically significant correlation between the preoperative and the postoperative degrees of glottic insufficiency. It was not always possible to close large glottic gaps completely in every case. Despite good overall results we experienced some limitations of the implant and the surgical technique as well. We therefore began to modify the implant and the surgical technique on the basis of anatomic and experimental studies. CONCLUSIONS: External vocal fold medialisation proved to be a safe and well tolerated surgical procedure. It is reversible and revisable, suitable for nearly all kinds of glottic insufficiencies, and can be combined with other phonosurgical procedures. Significant reduction of glottic insufficiency can usually be achieved, although large glottic gaps cannot be closed completely in every case. It should be possible to overcome certain limitations of the currently performed technique by developing new implants and modified surgical procedures. External vocal fold medialisation could then become established as a standard procedure providing even better and more stable functional results, at minimal risk to the patient.

Adult↗
PubMed1998

[External vocal cord medialization: functional outcome].

BACKGROUND: Comprehensive evaluation of voice function is the precondition for indication and quality control of every phonosurgical procedure. In 53 patients presenting with glottic insufficiencies of different etiologies an external vocal fold medialisation was performed. Functional voice results obtained with this operation are presented and discussed. METHODS: The following voice parameters were measured preoperatively and postoperatively, and statistical comparison was performed: mean fundamental frequency and sound pressure level, frequency and intensity range (voice range profile), perceptual evaluation of hoarseness, and maximum phonation time. The impairment of vocal communication skills was rated on a newly developed 7-point scale. A combined parameter called "Voice Dysfunction Index" was introduced for global assessment of vocal abilities in particular for long term observations. RESULTS: Statistically significant improvement of all voice parameters was demonstrated. Interestingly, in nearly all measurements male patients yielded significantly better results than females. Glottic insufficiencies due to scarring produced poorer functional results but without statistical significance. A statistically significant correlation between the preoperative and postoperative Voice Dysfunction Index could be observed. This score was also significantly correlated with the degree of glottal gap. No significant correlation between voice results and preoperative delay or follow-up period were observed. Voice therapy was performed in 81% of the patients. Correlation of duration of voice therapy and voice results was statistically significant and negative. Analysis of this surprising result showed that it was caused by some patients with vocal fold scarring in whom outcome was poor despite a long period of voice therapy. CONCLUSIONS: Significant improvement of vocal function can be obtained by external vocal fold medialization in patients with glottic insufficiencies. Glottal gaps caused by vocal fold scarring and/or atrophy can be treated with this method, too. However, results are not as good as in paralysis and require additional long term voice therapy. Satisfying results can be expected in patients with a long history of disturbances, and in older patients. Due to the reversibility of the operation, external vocal fold medialization can be performed even in cases of palsy prior to the spontaneous recovery period. The degree of glottic gap determines the functional disturbance. The degree of the preoperative impairment correlates with the outcome. Results are stable with respect to the follow-up period (mean 66 weeks).

Adult↗
PubMed1997

Cardiac troponin I to diagnose percutaneous transluminal coronary angioplasty-related myocardial injury.

The purposes of the present study were to evaluate cardiac troponin 1 (cTnl) in the diagnosis of percutaneous transluminal coronary angioplasty (PTCA)-related myocardial injury in comparison with cardiac troponin T (cTnT) and creatine kinase (CK) MB mass concentration, and to investigate the frequency of myocardial injury, as indicated by myocardial protein release, after clinically symptomless side-branch occlusion (SBO) which may occur in the proximity of the attempted stenosis. The final study population comprised 80 patients undergoing elective, single vessel PTCA. Blood samples were drawn before, 6, 24 and 48 h after PTCA. cTnI, cTnT and CKMB mass baseline values were within the reference intervals in all patients (cTnI < 0.1 microgram/l, cTnT < 0.2 microgram/l, CKMB < 5 micrograms/l). Two patients presented with primary failure of PTCA, and visually successful PTCA was performed in all remaining patients. Seven patients (four with SBO) subsequently developed acute myocardial infarction (AMI). Symptomless SBO occurred in 16 patients. In controls (n = 55) there were no significant increases in cTnI, cTnT, or CKMB concentrations compared with baseline values, and all markers stayed within their reference intervals. In half the patients with symptomless SBO (n = 8) all markers were slightly to moderately increased, in two additional patients only CKMB was elevated (cTnI: 0.1-1.0 microgram/l; cTnT: 0.25-0.81 microgram/l and CKMB: 7.9-25.6 micrograms/l). In the majority of patients with primary failure or AMI we found pronounced increases in all tested markers (cTnI: 0.2-12.0 micrograms/l; cTnT: 0.44-12.10 micrograms/l; CKMB: 19.2-423.0 micrograms/l). The results of this study indicate that cTnI is comparably useful to cTnT or CKMB mass for diagnosing myocardial injury in PTCA patients. From our results a preference for one of the tested parameters cannot be clearly derived. Post-procedural cTnI, cTnT, and CKMB mass values are not higher than baseline values in uncomplicated cases, whereas AMI after PTCA leads to pronounced marker increases. SBO, even when symptomless, leads frequently (in about half the patients) to slight marker increases.

Adult↗
PubMed1997

Surgical anatomy of the larynx.

Modern functionally oriented surgery of the larynx increasingly requires exact knowledge of the anatomy and landmarks of the endolaryngeal structures in relation to the laryngeal skeleton. Review of the literature reveals several opposing statements and controversial anatomical definitions regarding several clinically critical points. In order to obtain basic anatomical data morphological measurements were performed on a total of 50 laryngeal specimens. Measurements were taken on whole organs and on cuts in the horizontal and in the frontal plane, as well. The data were evaluated statistically, which resulted in the determination of average configurations and dimensions of cartilages and soft tissues of the larynx. In particular, the projection of the deeper structures on the surface and the distances and angles between the different structures were taken into consideration. In order to make these data clinically applicable a scale model has been developed that will allow a direct correlation and application for individual surgery.

Female↗
PubMed1997

Intestinal absorption of undegraded proteins in men: presence of bromelain in plasma after oral intake.

The human adult intestinal epithelium has traditionally been described as nonpermeable to proteins. However, indirect evidence suggests that reduced absorption of undegraded proteins might take place under physiological conditions. Using bromelain (an enzyme obtained from pineapple stems) as a model protein, we studied the extent of this mucosal permeation in 19 healthy men. The protein was detected in plasma by immunoassay and by its proteolytic activity after oral administration. The estimated plasma half-life was 6-9 h. After oral multidosing (3 g/day), plasma concentration reached as much as 5,000 pg/ml by 48 h. From the plasma concentration curve, it could be estimated that an average of 10.8 micrograms of bromelain was present in plasma in the 3- to 51-h period. The presence of undegraded bromelain in plasma was shown unequivocally by immunoprecipitation of plasma samples with antibromelain antibodies, followed by gel electrophoresis and immunodetection. Moreover, the enzyme retained its biological activity, at least in part. Circulating bromelain was found associated with alpha 2-macroglobulin and alpha 1-antichymotrypain. The results of this work confirm the existence of a small but significant intestinal transport of undegraded proteins in healthy men.

Administration, Oral↗
PubMed1997

Value of exfoliative cytology in differential diagnosis of epithelial hyperplastic lesions of the larynx.

In a comparative random study we examined material from suspicious laryngeal lesions from 85 patients. Material was obtained simultaneously by exfoliative cytology and biopsy. The diagnoses included keratosis, papilloma/papillomatosis, dysplasia/carcinoma in situ and invasive carcinoma. In each case we were able to demonstrate the cytological diagnostic criteria in the respective histological specimens. We illustrate this in the paper with some examples. Due to the excellent correlation between cytology and histology we are convinced that exfoliative laryngeal cytology is very significant in differential diagnosis of epithelial hyperplastic lesions.

Biopsy↗