[Functional outcome after transmandibular resection and primary chemoradiation in advanced oropharyngeal squamous cell carcinoma]. / Funktionelle Ergebnisse nach transmandibulärer Resektion und primärer Radiochemotherapie bei fortgeschrittenen Kopf-Hals-Plattenepithelkarzinomen.

OBJECTIVE: The aim of this study was to assess the functional outcome after transmandibular resection and reconstruction via a radial forearm flap (TMR+RFF) compared to primary chemoradiotherapy (pCRT) in advanced oropharyngeal squamous cell carcinoma (OPSCC). METHODS: The study compared 50 OPSCC patients treated with TMR+RFF to 50 OPSCC patients receiving pCRT. The time taken to swallow water served as the primary endpoint. The Saxon test, maxillomandibular distance, Mallampati score, ratio of height to weight, nasal penetration, tracheostomy/gastral tube requirement, and four validated questionnaires (visual analog scale for xerostomia, Sicca VAS; MD Anderson Dysphagia Inventory, MDADI; Voice Handicap Index, VHI; European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, Head and Neck Cancer, 35 items, QLQ-H&N35) were applied to access functionality and quality of life. RESULTS: Patients after TMR+RFF showed an increased rate of nasal penetration (p < 0.0001), which was associated with a longer water swallowing time (p < 0.05). A modified reconstruction of the soft palate significantly decreased the rate of nasal penetration in comparison to classical reconstruction (p = 0.0001). Patients with pCRT suffered significantly more xerostomia (Saxon test) than patients with TMR+RFF and adjuvant therapy. None of the subjective questionnaires revealed significant differences between the groups. CONCLUSION: TMR+RFF with modified reconstruction and adjuvant treatment and pCRT showed comparable functional outcomes.

[Stomal Cancer Recurrency, A Clinic-Pathological Consideration]. / Stomarezidive, eine klinisch-pathologische Betrachtung.

Objectives: Analysis of pre-operative tracheostomy and circumjacent tumour free margins as risk factors in the development of stomal recurrent disease after (pharyngo)laryngectomy. Material and Methods: 124 patients after (pharyngo)laryngectomy were analyzed for disease related data and tumour samples were analyzed for tumour free margins. The overall cohort was divided into patients with/withour pre-operative tracheostomy. Results: 18 patients suffered from recurrent disease (10 stomal, 8 distant metastases). Advanced T-status, female gender, and sub-/glottic tumour manifestation resulted in a higher rate of prior tracheostomy. Pre-operative tracheostomy did not influence the development of stomal recurrency. R0 resection was achieved in 94% of our patients, with significant reduced tumour free margins in patients with stomal recurrency (p=0.002) Conclusion: Pre-operative tracheostomy did not influence the development of stomal recurrent disease. The clinical identification of ventral soft tissue infiltration should result in extensive surgical concepts.

[Current surgical and adjuvant therapy concepts of malignant tumors of the facial skin and the pinna]. / Aktueller Stand der chirurgischen und adjuvanten Therapie der Malignome der Gesichtshaut und der Ohrmuschel.

Malignant tumors of the skin had been a rare entity 2 decades ago. Today they are spread rapidly worldwide. Malignant neoplasms of the skin, the largest human organ, may occur from all structures and layers. While previously skin cancer -occurred mainly after the age of 60, the incidence increases now in younger ages. Strong sunburns in the childhood and before the age of 20 are important risk factors for the development of malignancies of the skin. An increased exposure to UV rays is found especially in the facial skin, where basal cell carcinoma, squamous cell carcinoma, malignant melanoma and Merkel cell carcinomas are the most common malignancies. Early diagnosis of malignancies and therapy-oriented mostly surgical approaches are crucial for the prognosis of all skin cancers. Therefore under the aspect of the increasing incidence these topics will be pointed out according to the latest findings including current multimodal therapy concepts and future treatment options.

In vitro chemosensitivity of head and neck cancer cell lines.

BACKGROUND: Systemic treatment of head and neck squamous cell carcinoma (HNSCC) includes a variety of antineoplastic drugs. However, drug-resistance interferes with the effectiveness of chemotherapy. Preclinical testing models are needed in order to develop approaches to overcome chemoresistance. - METHODS: Ten human cell lines were obtained from HNSCC, including one with experimentally-induced cisplatin resistance. Inhibition of cell growth by seven chemotherapeutic agents (cisplatin, carboplatin, 5- fluorouracil, methotrexate, bleomycin, vincristin, and paclitaxel) was measured using metabolic MTT-uptake assay and correlated to clinically-achievable plasma concentrations. - RESULTS: All drugs inhibited cell growth in a concentration-dependent manner with an IC50 comparable to that achievable in vivo. However, response curves for methotrexate were unsatisfactory and for paclitaxel, the solubilizer cremophor EL was toxic. Cross-resistance was observed between cisplatin and carboplatin. - CONCLUSION: Chemosensitivity of HNSCC cell lines can be determined using the MTT-uptake assay. For DNA-interfering cytostatics and vinca alkaloids this is a simple and reproducible procedure. Determined in vitro chemosensitivity serves as a baseline for further experimental approaches aiming to modulate chemoresistance in HNSCC with potential clinical significance.

[Risk of hemorrhage after adenoidectomy and tonsillectomy. Value of the preoperative determination of partial thromboplastin time, prothrombin time and platelet count]. / Risiko von Blutungen nach Adenotomie und Tonsillektomie. Aussagekraft der präoperativen Bestimmung von PTT, Quick und Thrombozytenzahl.

BACKGROUND: Hemorrhage after tonsillectomy and adenoidectomy remains a serious complication. Therefore, routine preoperative coagulation screening, including activated partial thromboplastin time (aPTT), prothrombin time (PT) and platelet count (PLC), are regularly performed, also for medicolegal reasons. In the recently published statement of the German Society of Otorhinolaryngology, Head and Neck Surgery the need for routine preoperative coagulation screening is discussed, but so far no standardized procedure had been established. According to this statement - at least for children - routine preoperative coagulation screening is not mandatory as long as the thorough medical history provides no evidence for a coagulation disorder ( http://www.hno.org/kollegen/gerinnung_te_ae.html ). The present study was undertaken to determine the occurrence of postoperative hemorrhage on the one hand, and the incidence of abnormal preoperative routine coagulation parameters or pathological anamnesis findings on the other. PATIENTS AND METHODS: In 688 patients, a standardized clinical history was obtained using a questionnaire. Coagulation screening included aPTT, PT, and PLC was also carried out. Bleeding complications were then correlated with anamnesis features and abnormalities in coagulation screening. RESULTS: In 39 (5.7%) of the 688 patients we found abnormal coagulation values, which were confirmed in repeated analyses. In six of these a detailed analysis revealed occult coagulation disorders requiring correction only in the case of bleeding complications who were previously unknown. Fifteen patients were already known to have a coagulation disorder, and the anamnesis identified no additional patient at risk. Thus, 21 patients with coagulation disorders requiring correction in the case of a bleeding complication underwent surgery. However, only eight (38%) of these showed abnormal routine coagulation parameters. Surgical treatment of postoperative hemorrhage was required in 12 patients, all of whom had normal values for aPTT, PT and PLC. CONCLUSION: The frequently performed determination of routine coagulation parameters (aPTT, PT, PLC) is not able to reliably identify relevant coagulation disorders or to predict the risk for postoperative hemorrhagic complications after adenoidectomy or tonsillectomy.

Which kind of frontal mandibulotomy is the smartest? A biomechanical study.

PURPOSE: Retrospective clinical evaluation and biomechanical tests were performed to compare the primary stability and the rate of pseudarthrosis formation after irradiation for two types of mandibular split osteotomies: the stairstep osteotomy (SSO) and the straight-line osteotomy (SLO). METHODS: The postoperative occurrence of pseudarthrosis was retrospectively analysed in 46 non-consecutive clinical cases of SSO and SLO between 2003 and 2013. Biomechanical tests were performed on 12 standardised synthetic mandibles (Synbone) to compare the SSO and SLO approaches. Two 2.0 mm monocortical miniplates (Medartis) were used for osteosynthesis. The artificial mandible specimens were loaded to 300 N on the Mandibulator test bench while interfragmentary motion was measured using the PONTOS optical measurement device. RESULTS: The retrospective clinical analysis showed a rate of pseudarthrosis of 19% in the SLO group versus only 5% in the SSO group (p = 0.17). In the biomechanical investigation, the average interfragmentary movement was 14.3 ± 7.70 for the SLO group and 4.57 ± 2.33 for the SSO group under a maximum load of 300 N, resulting in a statistically significant difference between the two approaches (p = 0.014). CONCLUSION: To minimise the rate of postoperative pseudarthrosis formation, SSO is superior to SLO for mandibular split procedures, because SSO provides greater resistance to vertical loads and allows less interfragmentary movement. LEVEL OF EVIDENCE: 2C (Outcomes research).

Chemosensitivity of head and neck squamous carcinoma cell lines is not primarily correlated with glutathione level but is modified by glutathione depletion.

Glutathione has a variety of important physiological functions in cellular metabolism and defense, including protection from radicals, oxidative stress, and electrophilic compounds. On the basis of this interaction with both endogenous and synthetic substances, glutathione and the key enzyme for its conjugation, glutathione S-transferase, appear to be critical determinants in tumor cell resistance to several antineoplastic drugs, e.g. platinum analogs. In ten established head and neck cancer cell lines (UM-SCC 10A, 10B, 11B, 14A, 14B, 14C, and 22B, HLac79, 8029NA, and 8029DDP4) chemosensitivity to cisplatin, carboplatin, 5-fluorouracil, and bleomycin, as well as cellular glutathione content and activity of glutathione S-transferase were determined. The results revealed no correlation between the sensitivity of tumor cells to any of the drugs tested and the level of glutathione or the activity of glutathione S-transferase. However, the cisplatin-resistant subpopulation 8029DDP4 showed the highest glutathione level and marked cross-resistance to bleomycin. Glutathione depletion with buthionine sulfoximine led to moderately increased sensitivity towards cisplatin and carboplatin in all cell lines, but did not affect their response to 5-fluorouracil or bleomycin. These results suggest that the level of glutathione or the activity of glutathione S-transferase is not a suitable parameter for the assessment of chemosensitivity in head and neck squamous-cell carcinoma lines. However, response to platinum analogs is influenced by alterations of the initial intracellular glutathione concentration.

Clinical trial with escalating doses of the antiepidermal growth factor receptor humanized monoclonal antibody EMD 72 000 in patients with advanced squamous cell carcinoma of the larynx and hypopharynx.

In this open uncontrolled phase I study, nine patients with stage III and IV squamous cell carcinoma of the head and neck (SCCHN) were treated with five administrations of the humanized antiepidermal growth factor receptor monoclonal antibody EMD 72000 in three consecutive ascending dose groups. Loading doses of 100 mg (group I), 200 mg (group II), and 400 mg (group III) were followed by four weekly maintenance doses of half the loading doses, i.e. 50, 100, and 200 mg, respectively. Two EMD 72000 administrations were scheduled before and three after surgery. The objectives of this trial were (a) to investigate the safety and toxicity of multiple EMD 72000 doses, (b) to determine the cumulative maximum tolerated dose of EMD 72000 at dosages between 300 mg and 1,200 mg, and (c) to determine the serum pharmacokinetics of EMD 72000. In total, 102 adverse events (AEs) were reported: five of toxicity grade 3, 18 of toxicity grade 2, 66 of toxicity grade 1, and 38 of toxicity grade 0. All AEs of toxicity grade 3 were considered to be not or remotely related to EMD 72000. The most frequent study drug-related AEs were fever and a transient elevation of liver enzymes. In all patients, the time to reach peak serum concentrations (tmax) was within 1-3 h of the start of each EMD 72000 infusion. Average peak serum concentrations (Cmax) after correction for dosage appeared to be dose-independent, whereas the half-life (t1/2) showed dose dependency. In conclusion, EMD 72000 was very well tolerated in patients with advanced stage SCCHN. The pharmacokinetic data from this trial suggest the feasibility of conducting future studies with weekly doses of 200 mg EMD 72000.

Intratumoral BCG therapy of transplanted head and neck tumors in strain 2 guinea pigs.

The generally unfavorable prognosis associated with advanced squamous cell carcinoma in the head and neck region in humans led us to immunotherapeutic experiments with bacillus Calmette-Guerin (BCG) in inbred guinea pigs with solid growing and lymphogenous metastasizing tumors. The injection of live BCG or BCG cell wall preparation (CWP) into the planum buccale in the guinea pig led to a pronounced local inflammatory reaction. If live BCG or BCG CWP were injected into the planum buccale together with line 10 tumor cells, no growth of the tumor could be observed. Animals treated in this manner developed a tumor-specific immunity. Guinea pigs treated intratumorally with live BCG or BCG CWP in established, 6-day-old tumors of the planum buccale showed regression of the primary tumor and prevention of the development of lymph node metastases. These cured animals also developed a tumor-specific immunity. Guinea pigs with 6-day-old tumors of the planum buccale remained tumor free after surgical removal of the primary tumor and the draining submandibular and cervical lymph nodes (radical operation) whereas locally operated animals (primary tumor excision) developed lymph node metastases. Animals that were tumor free after radical surgery did not develop tumor-specific immunity. Despite insufficiently clarified mechanisms for the induction and effect of BCG immunotherapy, we can state that, with intratumoral BCG therapy, a tumor experimentally placed in the head and neck region is eliminated, regionally manifest metastases are eliminated, and specific tumor immunity can be demonstrated in successfully treated animals.

Serum level and tissue expression of c-erbB-1 and c-erbB-2 proto-oncogene products in patients with squamous cell carcinoma of the head and neck.

The proto-oncogene products erbB-l (EGF-Receptor) and erbB-2 (HER-2/neu), distinct members of the epidermal growth factor receptor family, are frequently overexpressed in squamous cell carcinoma of the head and neck (SCCHN). The accumulation of these transmembrane proteins may lead to significant amounts of the respective extracellular receptor domains (ECD) that are shed from the tumour cell surface and enter blood circulation, thus representing potential serum tumour markers. For erbB-l and erbB-2, we determined the ECD serum levels with enzyme-linked immunosorbent assays and evaluated the protein expression in tumour tissue by immunohistochemistry. The present study included 49 patients (37 untreated, 12 recurrences) and the same number of age- and sex-matched healthy controls. In 24 patients ECD serum levels were determined before and 6 weeks after surgery. Mean ECD serum levels for erbB-1 and erbB-2 were 54.8+/-1.6 and 153.7+/-6.1 fmol/ml in cancer patients, and 54+/-1.5 and 147.9+/-4.5 fmol/ml in healthy controls, respectively. There was no significant difference between untreated and recurrent disease. Serum ECD follow-ups 6 weeks after surgery revealed a significant 12.3% decline of erbB-1 but no change of erbB-2 values. Immunohistochemistry showed strong staining for erbB-1 in 78% and erbB-2 in 47% of the SCCHN specimens. No correlation was detectable between receptor ECD serum levels and receptor tissue expression, tumour stage, and tumour differentiation. Hence, ECD serum levels of erbB-1 and erbB-2 are not considered to be valuable tumour markers in SCCHN.

Antitumor activity of anti-epidermal growth factor receptor monoclonal antibodies and cisplatin in ten human head and neck squamous cell carcinoma lines.

Head and neck squamous cell carcinomas (HNSCC) frequently display increased levels of epidermal growth factor receptor (EGFR) and since the receptor is located on the cell surface, anti-EGFR antibodies appear to be suitable agents for antitumor therapy. We investigated the effect of murine EMD 55900 and rat ICR 62 monoclonal antibodies (MAb) directed against EGFR both as single agents and in combination with cisplatin. ELISA detection showed the amount of EGFR protein in HNSCC lines UM-SCC-10A, -10B, -11B, -14A, -14B, 14C, -22B and HLac 79, 8029NA, 8029DDP to range between 20 and 8100 fmol/mg protein. Compared to A431 cells, seven HNSCC lines were high and three low receptor expressors. Only low levels of TGF alpha were found in the supernatants of some untreated HNSCC lines, probably due to the consumption of TGF alpha by EGFR. Consequently, occupation of EGFR by MAb led to marked accumulation of TGF alpha in cell supernatants. Colorimetric MTT assay showed both MAbs (0.3-30nM) to have comparable dose-dependent growth inhibition which correlated with the EGFR content of the respective cell lines (p < 0.05). Using 30nM MAb, seven high receptor expressing HNSCC lines were growth inhibited by at least 20% to a maximum of 61% (mean = 38%). Combined treatment with MAb and cisplatin led to a significant decrease in cisplatin IC50 values in 5 cell lines expressing more than 1200 fmol EGFR/mg (dose modification by factor 2.1-4.1). In conclusion, anti-EGFR MAb exert direct antiproliferative activity in HNSCC lines and show additive effects in combination with cisplatin.

Establishment and characterization of four cell lines derived from human head and neck squamous cell carcinomas for an autologous tumor-fibroblast in vitro model.

To study interactions between tumor cells and stromal elements, we established carcinoma cell lines as well as tumor-derived and skin fibroblast cultures from four patients with squamous cell carcinoma of the head and neck. For the characterization of the tumor cell lines we a) determined population doubling times, b) assessed morphological features by light and electron microscopy, c) investigated the expression of typical markers by immunohistochemistry, including various intermediate filaments and surface antigens, d) compared these findings with expression patterns in the respective original tumor specimens, e) evaluated p53 mutations in tumor specimens and cell lines, f) performed chromosome analysis, g) investigated the tumorigenicity in athymic mice, and h) tested the formation of both tumor and mixed tumor-fibroblast multicellular spheroids. Tumor cell cultures were considered established cell lines when maintained and passaged over a period of two years after primary explantation. The in vitro morphology of the cell lines showed well preserved characteristics of squamous cell carcinoma, and electron microscopy as well as immunohistochemistry revealed their squamous type of differentiation. All cell lines presented the same p53 genotype as the respective original tumors. Furthermore, they were successfully xenotransplanted into nude mice and formed both pure and mixed three dimensional spheroids. This experimental model allows the in vitro and in vivo investigation of various tumor-fibroblast interactions.

Dual role of fibroblasts in tumor cell growth.

Vast experience with cultivating biopsies from human tumors indicates that in most cases the admixture of fibroblasts has a negative effect on growth of tumor cells. Only rarely is observed help provided by the fibroblasts. It has also long been known that fibroblasts can inhibit by contact themselves and also produce growth factor(s) promoting cell proliferation. We have used three permanent squamous cell carcinoma lines and fibroblasts derived from biopsies of trachea to study this paradox. The inhibitory activity of fibroblasts is contact-dependent in a cell membrane-bound factor, which is trypsin sensitive. We prepared microsomal fractions (MF) from aged (more than 40 passages) fibroblasts and followed their effect on proliferation of the tumor cell lines in MTT assay. MF from all three fibroblast lines inhibited the tumor cells. Most regularly was this phenomenon observed with line UM-SCC 22B. Not all tumor cells are immortal. On the contrary, a large portion of them undergoes terminal differentiation. With the line UM-SCC 22B we tested the possibility that MF from fibroblasts can increase the portion of tumor cells which will senescence after few mitoses. The immortal cells were defined as cells capable in 8 or 13 days of forming colonies of more than 50 or 200 cells. The senescent cells were defined as cells not capable of producing within the same period of time colonies of more than 12 or 30 cells. The MF was able to increase the number of small colonies, i.e. the number of senescent tumor cells. The fibroblasts of the same passage level were releasing soluble growth factor(s) promoting growth of cells. Fibroblasts can apparently simultaneously inhibit growth by contact and release factor(s) promoting growth of cells. The final outcome is a result of the balance between these two forces. This balance is regulated by many intrinsic and extrinsic forces.

Circumvention of drug resistance in cisplatin-resistant sublines of the human squamous carcinoma cell line HLac 79 in vitro and in vivo.

In a previous report we have characterized cisplatin (CDDP)-resistant sublines (HLac 79-DDP1 to DDP4) of the recloned squamous cell head and neck cancer (SCHNC) line HLac 79-ML revealing significant alterations of glutathione (GSH) metabolism and drug accumulation. In order to overcome CDDP-resistance in HLac 79 cells we now investigated the effect of buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis, verapamil (VRP), a calcium channel blocker that has been found to modulate resistance towards a broad spectrum of antineoplastic drugs, cyclosporin A (CSA), an immunosuppressive agent probably affecting drug pharmacokinetics, and aphidicolin (APC), a fungal metabolite interfering with DNA repair through inhibition of DNA polymerase alpha, on HLac 79 CDDP-sensitivity. Using the colorimetric MTT assay, GSH depletion with BSO led to a significant decrease of the 50% inhibitory drug concentration (IC50) in all HLac 79 sublines by dose modifying factors (IC50 CDDP/IC50 BSO + CDDP) ranging from 1.8 to 3.3. VRP, CSA or APC were not effective to overcome CDDP resistance in HLac 79 cells. The potential of BSO to modulate CDDP resistance in vitro was tested in vivo in HLac 79 tumor bearing NMRI nu-nu mice subsequently. Oral administration of BSO 7 days prior and during (days -7 to 8) CDDP treatment (3 mg/kg bw i.p. days 0, 4, 8) produced a significant prolongation of mean survival time mean as compared to chemotherapy alone. This held true for both the maternal line ML in terms of chemosensitization (CDDP: mean = 40.2 +/- 15.9 days vs. CDDP + BSO: mean = 80.3 +/- 30.4 days, p less than 0.001) and the CDDP resistant subline DDP4 in terms of partially overcoming secondary drug resistance (CDDP: mean = 56.5 +/- 13.6 days vs. CDDP + BSO: mean = 72.5 +/- 15.8 days, p less than 0.001). Enhanced toxicity of combined BSO and CDDP treatment manifested by transient 10% reduction of animal mean body weight.

Establishment and characterization of cisplatin-resistant sublines of the human squamous carcinoma cell line HLac 79.

Though various chemotherapy protocols lead to considerable response rates in squamous cell head and neck cancer (SCHNC), the overgrowth of a tumor cell phenotype which no longer responds to clinically achievable drug concentrations regularly impairs definite tumor control. In order to investigate mechanisms of drug resistance towards one of the most active agents in SCHNC we established four Cisplatin (CDDP)-resistant sublines (DDP1-DDP4) of the recloned human SCHNC cell line HLac 79. The 50% inhibitory drug concentration (IC50) of CDDP as determined by the colorimetric MTT-assay was increased by the factors 2.7 (DDP1), 3.3 (DDP2), 5.1 (DDP3), and 6.4 (DDP4) in the respective sublines. Three subpopulations contained significantly elevated glutathione (GSH) levels by the factors 1.4 (DDP3), 1.7 (DDP2), and 2.4 (DDP4) compared to the maternal line (50.2 nM/mg protein). DDP4 showed increased activity of gamma-glutamyl-transpeptidase (1.83 vs. 1.21 mU/mg protein), and DDP2 and DDP4 showed increased activity of GSH-S-transferase (35.6 and 51.9 vs. 25.1 mU/mg protein). Concerning both GSH-peroxidase and GSH-reductase no significant differences between the HLac 79 subpopulations were observed. Intracellular CDDP accumulation determined by neutron activation analysis revealed reduced drug uptake in DDP3 and DDP4 (60% and 76% of control value).

[Emergency management of acute angioedema]. / Notfallsituation akutes Angioödem.

Angioedema is an oedematous swelling of the mucosa or submucosa of the skin. Acute angioedema represents a clinical emergency when the pharynx or larynx are involved and breathing of the patient is impaired. For rapid and effective treatment it is necessary to differentiate between allergic and non-allergic angioedema. Three of the five subforms of non-allergic angioedema are mediated by bradykinin: renin-angiotensin-aldosterone system (RAAS)-blocker-induced angioedema (RAE), hereditary angioedema (HAE) and acquired angioedema (AAE). Antihistamines, corticosteroids and adrenalin can be used to treat allergic angioedema but are ineffective in acute attacks of non-allergic angioedema. In these events the bradykinin-B2-receptor antagonist icatibant (in HAE, or RAE) or C1-INH concentrate (in HAE, or AAE) are therapeutic options for rapid alleviation of acute angioedema. The following article gives an overview of the diagnostics and treatment in the emergency situation of "acute angioedema", especially if swelling of the head-and-neck region is present.

[ACE-inhibitor induced angioedema]. / Das ACE-Hemmer-induzierte Angioödem.

ACE-inhibitor induced angioedema is a non-allergic drug-related side effect. Inhibited bradykinin degradation leads to an unphysiological enhanced bradykinin plasma level with vascular leakage and, consequently, to angioedema. ACE-inhibitor induced angioedema develop rapidly in the head and neck region. Typical sites of manifestation are lips, tongue, and larynx. Novel pharmacotherapies may allow a causal treatment of the ACE-inhibitor induced angioedema in the future.