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Biomedical subjects

W Lehmann

Publications and source records attributed to W Lehmann.

At least 55 records · Page 3Linked to original sources
PubMed1999

A complication of intraoperative facial nerve monitoring: facial skin burns.

OBJECTIVE: To report on three cases of severe facial skin burns resulting from intraoperative facial nerve monitoring in patients undergoing parotidectomies. STUDY DESIGN: This study is a retrospective case review. SETTING: A tertiary referral center. PATIENTS: This study includes three patients who underwent parotidectomies with concurrent facial nerve monitoring. RESULTS: Facial skin burns were proven to result from a technical defect of the intraoperative facial nerve monitoring device. Burns were sustained at electrode insertion sites and their extent was related to the duration of monitoring. The most probable explanation of these burns is electrolysis. CONCLUSIONS: Successful retracing of technical defaults with biomedical engineers at the device manufacturer have led to the upgrade of the facial nerve monitor apparatus. The benefits of facial nerve monitoring largely outweigh the fortuitous occurrence of skin burns reported in this study. Therefore, this complication should not represent a drawback to the use of facial nerve monitoring.

Adult↗
PubMed1998

Multivariate logistic analysis of dose-effect relationship and latency of radiomyelopathy after hyperfractionated and conventionally fractionated radiotherapy in animal experiments.

PURPOSE: We examined in rats whether the radiation tolerance of spinal cord is enhanced by using hyperfractionated radiotherapy compared to a conventional schedule. Higher tolerable doses to the spinal cord would allow dose escalation to the tumor and thus possibly lead to higher cure rates, especially in tumors with high cell proliferation. METHODS AND MATERIALS: Cervical spinal cord of 276 healthy rats was irradiated over 6 weeks hyperfractionally with single doses ranging from 0.75-2.5 Gy up to total doses ranging from 45-150 Gy (60 fractions) and conventionally with single doses of 1.5-4.0 Gy up to total doses of 45-120 Gy (30 fractions). The rats were examined neurologically and sacrificed when paralysis of the hind legs occurred. After fixation, spinal cord was removed and examined histologically. Dose-effect relationship and latency from the beginning of radiotherapy to the onset of paralysis were computed and analyzed using a multivariate logistic regression model. RESULTS: The model fitted the observed data excellently. There were highly significant effects both for the dose level and for the treatment regimen. Latency analysis showed earlier and more intense acute side effects after hyperfractionation but radiomyelopathy occurred markedly later. CONCLUSIONS: The sparing effect of hyperfractionation on spinal cord as predicted by radiobiologists could be confirmed in our experiments. Thus, it seems possible to escalate tumor doses using hyperfractionation without enhanced risk to spinal cord but with higher probability of tumor cure.

Animals↗
PubMed1998

Atypical squamous cell carcinoma of the larynx and hypopharynx: radiologic features and pathologic correlation.

The objective of this study was to analyze the radiologic features of atypical forms of squamous cell cancer and correlate them with clinical, endoscopic, and histopathologic findings. The CT and MRI images of 31 patients with atypical forms of squamous cell carcinoma were reviewed retrospectively and the radiologic findings were correlated with clinical, endoscopic, and histopathologic findings. Histopathologic diagnoses included undifferentiated carcinoma of nasopharyngeal type (n = 8), verrucous carcinoma (n = 18), spindle cell carcinoma (n = 3), and basaloid cell carcinoma (n = 2). Undifferentiated carcinoma of nasopharyngeal type was located in the supraglottis or piriform sinus beneath an intact mucosa and initial endoscopic biopsy was most often negative. The discrepancy between an intact mucosa at endoscopy and a solid mass with homogenous enhancement at CT or MRI was characteristic for these tumors and warranted further investigations to obtain the definitive histologic diagnosis. Verrucous carcinoma displayed characteristic clinical, radiologic, and pathologic features, namely, an exophytic tumor arising from the glottic level displaying a rugged surface with finger-like projections but with only minor submucosal infiltration. Spindle cell carcinoma appeared as a polypoid mass with a thin stalk arising from the supraglottis. Basaloid cell carcinoma displayed a distinct lobulated enhancement pattern which was observed on contrast-enhanced T1-weighted SE images. Although the MR and CT features of atypical forms of squamous cell carcinoma cannot be considered pathognomonic they should raise the differential diagnosis even if endoscopic biopsy has been negative. The radiologist's awareness of the appearance of these unusual tumors on CT and MR images may greatly facilitate the diagnostic work-up and helps to guide the endoscopist to the adequate biopsy site in order to establish the correct diagnosis.

Aged↗
PubMed1998

Early diagnosis of cognitive impairment in the elderly with the focus on Alzheimer's disease.

In dementia disorders, it can be assumed that the pathological process in the brain has been present for a long time. It is therefore of importance to have a preclinical or an early clinical diagnosis. Obviously, vulnerability genes, such as ApoE-4, can be diagnosed preclinically. As we have no treatment to offer patients with genetic risk factors, genotyping for ApoE-4 is at present of no clinical use. Trained neuropsychologists have today access to sensitive tests which reveal cognitive impairment before the disturbances reach the level of dementia. Laboratory investigations of cerebrospinal fluid have so far yielded no great results. Tau protein appears to be the most sensitive marker, but it is unspecific. Chromogranin A separates early onset from late onset Alzheimer's disease and seems to be a marker for synaptic degeneration. Synaptotagmin was also found to be reduced in patients with early onset Alzheimer's disease. Still we do not know, however, whether these proteins are early markers for degenerative processes in the brain. Laboratory investigations of blood have not yielded markers of use in early or differential diagnosis of dementia disorders. In a study at our own institute, however, we found serum-homocysteine (S-HCY) to be an early and sensitive marker for cognitive impairment. In patients with dysmentia (mild cognitive impairment), no less than 39% had pathological S-HCY levels, indicating insufficient 1-carbon metabolism.

Aging↗
PubMed1998

Concomitant boost radiotherapy in oropharynx carcinomas.

Fifty-five patients with resectable and unresectable oropharynx carcinomas were treated with concomitant boost radiotherapy. Forty-two of the patients (76%) had stages III-IV disease. Although none of the patients had undergone major surgery to the primary tumor, 11 had neck dissections prior to radiotherapy, and 19 (35%) received chemotherapy. The planned total tumor dose was 69.9 Gy, delivered over 5.5 weeks. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 13 fractions of 1.5 Gy each, as a second daily fraction in a progressively accelerated schedule; the prescribed dose outside the boost volume thus was 50.4 Gy. Median follow-up for surviving patients was 31.5 months (range: 16-65 months). All patients but one completed the planned radiotherapy schedule. According to the RTOG scoring system, 48 patients (88%) presented with grades 3-4 acute toxicity. The rate of grades 3-4 late complications was 12%. At three years the actuarial locoregional control rate was 69.5% and overall survival was 60%. We conclude that this concomitant boost schedule is feasible and does not seem to be associated with an excess risk of late complications. Acute toxicity was higher in association with chemotherapy, but remained manageable. Although the oncological results appear encouraging, evaluation of the efficacy of concomitant boost schedules compared with conventionally fractionated irradiation with or without concomitant chemotherapy requires prospective randomized trials.

Adult↗
PubMed1998

Bilateral radical neck dissection with unilateral internal jugular vein reconstruction.

OBJECTIVE: To describe and evaluate the functional and oncologic results of one internal jugular vein replacement after bilateral radical neck dissection (RND). STUDY DESIGN: A retrospective historical cohort study. METHODS: Since 1972 all patients (n = 9) undergoing bilateral RND with resection of both internal jugular veins had a reconstruction of one internal jugular vein. In six cases the RNDs were staged, and in three cases the RNDs were performed simultaneously. In every case a vascular reconstruction was performed with an autologous vein graft. All patients received radiation therapy, in five patients before and in four patients after the vein grafting. Functional results were evaluated in terms of postoperative head and neck and neurologic complications. In some patients a Doppler scan was performed to assess vein patency. Oncologic results are reported as relapse-free survival and mortality intervals. RESULTS: In all patients the postoperative course was uneventful, without neurologic complications. Facial edema was noted in four patients, mild in three and moderate in one. Two patients are alive, with follow-ups of 8 and 18 years. Seven patients are dead, two without evidence of recurrence, four with cervical recurrence after a mean survival of 10 months, and one after distant metastasis after a survival of 7 years. In patients with long-term survival a Doppler scan confirmed the patency of the vein graft. CONCLUSION: The lack of operative complications and the absence of postoperative neurologic complications make a unilateral internal jugular vein replacement after bilateral RND attractive, although the oncologic results remain poor.

Adult↗
PubMed1997

Feasibility and outcome of a progressively accelerated concomitant boost radiotherapy schedule for head and neck carcinomas.

PURPOSE: To evaluate toxicity and treatment outcome in patients with head and neck carcinomas treated with a modified bifractionated concomitant boost radiotherapy schedule. METHODS AND MATERIALS: Eighty-five patients were treated from February 1991 to October 1995. According to clinical TN stage 23 tumors were T1, 33 T2, 20 T3, 9 T4, 44 N0, and 41 N1-N3. The primary tumor was located in the oral cavity in 6 patients, oropharynx in 36, larynx in 19, hypopharynx in 17, and nasopharynx in 7. The basic treatment delivered 50.4 Gy in 28 fractions, once a day, to the primary site and both sides of the neck. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 13 fractions of 1.5 Gy each as a second daily fraction in a progressively accelerated schedule (total dose 69.9 Gy). Eighteen patients had a uni- or bilateral neck dissection, and 2 an adenectomy before radiotherapy. The median follow-up for the surviving patients was 28 months (range: 3-61 months). RESULTS: All the patients completed the planned radiotherapy schedule. According to the RTOG scoring system, 57 patients (67%) presented with Grade 3-4 acute toxicity. Grade 3 dysphagia was observed in 20 patients (23.5%). Three patients died during the 3 months following the treatment. Among 73 patients evaluable for late effects, five developed Grade 3-4 complications. At 3 years actuarial loco-regional control was 67% and overall survival was 62%. CONCLUSIONS: Although longer follow-up is needed to evaluate the definitive results, we conclude that this particular concomitant boost schedule is feasible and appears to be effective. While acute toxicity was greater than in monofractionated schedules, it was manageable, provided that supportive care measures were implemented in a timely fashion.

Adult↗
PubMed1997

Effect of arytenoid sparing during radiation therapy of early stage glottic carcinoma.

PURPOSE: To retrospectively evaluate the effect of arytenoid shielding on local control and complications in the treatment of early stage glottic carcinomas. MATERIALS AND METHODS: The analysis concerns 71 patients treated with megavoltage photons for stages Tis, T1 and T2 glottic carcinomas. In 31 patients the entire larynx was treated at 2 Gy/day to full dose (group 1, mean field area 41.5 cm2) and in 40 patients a posterior block was placed after a median dose of 54 Gy to protect the arytenoid cartilage (group 2, mean field area 38 cm2). The decision to shield 10-15 mm of the posterior aspect of the treatment volume was based on the presence or absence of involvement of the posterior third of the vocal cords. Median total dose was 70 Gy in both groups. RESULTS: RTOG grade 2 and 3 acute laryngeal complications were observed in 77% and 62.5% of patients in groups 1 and 2, respectively (P = 0.25). The rate of grade 2-3 late laryngeal complications (mostly arytenoid edema) was similar in the two groups (13.6% vs 20%, P = 0.83). Actuarial local control at 5 years was also similar in the two groups (T1: 85% vs 96.6%, P = 0.13 and T2: 82% vs 87.5%, P = 0.86). CONCLUSION: No objective differences could be shown in terms of acute or late laryngeal complications or in terms of local control related to the use of arytenoid shielding. As severe complications are rare and local control is very satisfactory using standard techniques, it is difficult to attribute any advantage to the use of arytenoid blocking.

Female↗
PubMed1997

Microscopic tonsillectomy: a double-blind randomized trial.

OBJECTIVE: To evaluate microsurgical bipolar cautery tonsillectomy (TEmic) by comparing it with traditional blunt dissection tonsillectomy (TEtrad). DESIGN: A double-blind prospective randomized trial with stratification in two age groups. PATIENTS: 200 consecutive patients undergoing tonsillectomy for tonsillar hypertrophy, or recurrent or chronic tonsillitis. OUTCOME MEASURES: Duration of surgery, intraoperative bleeding, daily postoperative pain and otalgia, postoperative bleeding episodes. METHODS: Duration of surgery and operative bleeding were evaluated by the anesthesiologist. The patients were instructed to record daily pain and otalgia. Final postoperative evaluation was done by a different physician, blinded to the surgical technique. RESULTS: Mean intraoperative bleeding was 12 ml for TEmic and 36 ml for TEtrad (P < 0.001). Mean duration of surgery was 37 minutes for TEmic and 36 minutes for TEtrad (NS). Otalgia was present in 41% of TEmic patients and 69% of TEtrad patients (p < 0.001). Daily postoperative pain was lower in the TEmic group than it was in the TEtrad group for the entire study period (10 days). Postoperative hemorrhage was present in three TEmic patients (3%) and in eight TEtrad patients (8%), a difference that did not reach significance (p > 0.1). CONCLUSION: Microsurgical bipolar cautery tonsillectomy compares favorably with traditional techniques in terms of intraoperative bleeding, postoperative pain, otalgia, and hemorrhage. This technique combines the hemostatic advantage of cautery dissection, the excellent visualization achieved by a microscope, and, with the use of a video, greatly improves the physician's ability to teach how to perform a tonsillectomy.

Biological Products↗
PubMed1997

Coping strategies, personality, and voice quality in patients with vocal fold nodules and polyps.

Emotional state affects the physiological mechanism involved in phonation. Differences in acoustical parameters of the voice under stress have been attributed to the coping mechanism used, which is based on the individual's perception of the situation. This study examines the relationship between coping strategies, personality, and voice in female subjects, ranging in age from 19.3-55.7 years, diagnosed with vocal nodules or polyps. The differences between coping strategies and personality are examined and compared with another group with no history of voice pathology. The relationship of personality and coping strategies to voice quality variables is reported. Results show that patients use emotional coping strategies more and cognitive coping strategies less than the comparison group. Type of voice pathology was found to be related to dominance, and a number of coping and personality variables were found to correlate significantly with voice quality.

Adaptation, Psychological↗
PubMed1997

Combined concomitant boost radiotherapy and chemotherapy in stage III-IV head and neck carcinomas: a comparison of toxicity and treatment results with those observed after radiotherapy alone.

BACKGROUND: Alteration of radiation therapy (RT) fractionation and the combination of chemotherapy (CT) with RT represent two predominant fields of current research in the treatment of head and neck carcinomas. To assess the potential integration of these two fields, a retrospective comparison of toxicity and treatment outcome was carried out in stage III-IV patients treated with a concomitant boost RT schedule with or without CT. PATIENTS AND METHODS: Fifty-two patients were treated by RT alone and 35 by RT and CT. In the RT group, there were significantly fewer T3-4 tumors (56% vs. 88%, P = 0.002) and higher proportion of planned neck dissections (35% vs. 14%, P = 0.047). The planned total dose was 69.9 Gy delivered over 5.5 weeks. In 10 cases CT was given before RT and in 25 concomitantly with RT, either alone or with neoadjuvant and/ or adjuvant CT. All patients but two had cisplatin-based (CDDP, 100 mg/m2) CT, associated in 28 patients with 5-fluorouracil (5-FU, 1000 mg/m2/24 h x 5). The median follow-up for the surviving patients was 21 and 31 months for the RT and RT-CT groups respectively. RESULTS: Grade 3-4 acute toxicity (RTOG) was observed in 73% and 36% of patients, and grade 3 dysphagia in 31% and 57% (P = 0.02) respectively in the RT and RT-CT groups. The rates of grade 3-4 late complications were similar in the two groups (5% vs. 12%). At three years, actuarial loco-regional control (LRC) was 57% and 66% (P = 0.66) and overall survival was 56% and 47% (P = 0.99) in the RT and RT-CT groups respectively. CONCLUSIONS: While acute toxicity was higher compared with RT alone, this accelerated RT schedule was feasible in association with 5-FU/CDDP, even administered concomitantly. Despite the significant proportion of more advanced disease in the RT-CT group, LRC was similar to that obtained by RT alone. Combinations of concomitant boost RT and chemotherapy merit further investigation in prospective trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Early and long-term results of an original accelerated radiation therapy schedule in head and neck carcinoma.

From November 1985 until October 1988, 39 patients with head and neck carcinoma (6 patients stage I-II and 33 stage III-IV) were treated with an accelerated radiotherapy schedule designed to deliver 69.6 Gy over a period of 5 weeks. Treatment was started with 20 Gy in 10 daily fractions to sites of initial macroscopic involvement, followed by bi-fractionated radiotherapy (2 x 1.6 Gy/day) to a larger head and neck volume. Twenty patients received neo-adjuvant chemotherapy. A homolateral radical neck dissection was performed in 2 patients. Twenty-six patients (66.6%) presented with acute grade 3 complications and 5 patients (13%) with grade 4 complications. Thirteen patients (33.3%) were hospitalized for supportive care. None of the patients who were evaluated on a long-term basis developed grade 3 or 4 late complications. The 5-year loco-regional control and overall survival rates were 62.4% and 33.6% respectively. Although acute toxicity is higher than in monofractionated schedules, it is manageable, and can be considered acceptable in the light of the apparently good loco-regional control thus obtained. This schedule is one of several accelerated radiotherapy programs which might merit study in prospective trials.

Adult↗
PubMed1996

SCO-spondin: a new member of the thrombospondin family secreted by the subcommissural organ is a candidate in the modulation of neuronal aggregation.

A number of cues are known to influence neuronal development including growth factors, cell-adhesion molecules, components of the extracellular matrix and guidance molecules. In this study, we present molecular and functional evidence that SCO-spondin, a novel relative of the thrombospondin family, could also be involved in neuronal development by modulating cell aggregative mechanisms. SCO-spondin corresponds to glycoproteins secreted by the subcommissural organ (SCO), an ependymal differentiation of the vertebrate brain located at the entrance to the Sylvian aqueduct. A cDNA clone of 2.6 kb, isolated from a bovine SCO cDNA library, was shown to be specifically and highly expressed in the bovine SCO by in situ hybridization and was subsequently sequenced. Analysis of the deduced amino acid sequence reveals the presence of four conserved domains known as thrombospondin (TSP) type I repeats. To account for the homology with thrombospondins and F-spondin, this secreted glycoprotein was called SCO-spondin. Two potent binding sites to glycosaminoglycan (BBXB) and to cytokine (TXWSXWS) are also found in the TSP type I repeats. The deduced amino acid sequence exhibits three other conserved domains called low density lipoprotein (LDL) receptor type A repeats. The possibility of SCO-spondin involvement in neuronal development as a component of the extracellular matrix is discussed regarding these molecular features. The idea of a modulation of cell-cell and/or cell-matrix interaction is further supported by the anti-aggregative effect observed on cultured neuronal cells of material solubilized from Reissner's fiber. That Reissner's fiber, the condensed secretory product of the SCO present along the whole spinal cord can be a potent morphogenetical structure is an important concept for the analysis of the molecular mechanisms leading to spinal cord differentiation.

Amino Acid Sequence↗
PubMed1996

The role of FDG-PET in the preoperative assessment of N-staging in head and neck cancer.

This prospective study based on 48 patients showed that FDG-PET has a significantly higher sensitivity for the detection of lymph node metastases compared with palpation and it appears that FDG-PET has a similar sensitivity to CT-scanning. According to our data, FDG-PET is a highly specific method in the evaluation of neck nodes. This new imaging technique allows a tridimensional study and is easy to interpret. Therefore, FDG-PET seems to be a valuable imaging technique for the detection of cervical lymph node metastasis.

Carcinoma, Squamous Cell↗
PubMed1995

[Deglutition disorders: from videofluoroscopy to rehabilitation].

Dysphagic patients present with swallowing difficulties that should be precisely localized and quantified in order to provide a specific rehabilitation. This paper describes a simple yet complete videofluoroscopy protocol with emphasis on each step of the swallowing process, in order to assess sequentially the physiopathology of the involved organs. A comparison is also established between the videofluoroscopy results and the specific rehabilitation to be cared by the swallowing pathologist.

Deglutition↗
PubMed1995

[Peritonsillar abscess. Emergency tonsillectomy?].

The treatment of peritonsillar abcess is still controversial: quincy tonsillectomy, also called tonsillectomy "à chaud" (TC) or interval tonsillectomy, also known as tonsillectomy "à froid" (TF), several weeks after incision and drainage. Of 105 patients presenting with peritonsilar abscess, 53 had tonsillectomy: 27 TC and 26 TF. For each group the following variables were analyzed: age, location of abscess, bacteriology, duration of surgery, amount of per-operative bleeding, post-operative hemorrhage and complications, and length of hospital stay. The location of the abscess was posterior in 33%, and therefore difficult to drain without tonsillectomy. Significant differences in favor of TC were found for: 1) the amount of per-operative bleeding; 2) the occurrence of post-operative hemorrhage; and 3) the duration of hospital stay. We conclude that TC is a safe procedure without increased risks, with less complications, and with a reduced cost. When surgery is indicated in the treatment of peritonsillar abcess, we advocate TC. From our results and the litterature a decision tree for the management of peritonsillar abcess is presented.

Abscess↗
PubMed1994

Ellagitannins and complex tannins from Quercus petraea bark.

The ellagitannins 2,3-(S)-hexahydroxydiphenoyl-glucose, pedunculagin, vescalagin, and castalagin; the flavanoellagitannins acutissimin A, acutissimin B, eugenigrandin A, guajavin B, and stenophyllanin C; and the procyanidinoellagitannin mongolicanin have been isolated from the bark of Quercus petraea. The ellagitannin fraction had a weak antisecretory effect.

Anthelmintics↗