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Biomedical subjects

W Wagner

Publications and source records attributed to W Wagner.

At least 91 records · Page 5Linked to original sources
PubMed1999

Clinical and microbiological efficacy of single dose cefuroxime prophylaxis for dental surgical procedures.

In a prospective controlled randomised trial of 59 patients the effect of a single dose of cefuroxime before multiple tooth extractions on the clinical findings and occurrence of bacteraemia was studied. In one group 1.5 g cefuroxime was administered intravenously 10 min before start of surgery. A total of 118 blood samples were collected after 10 and 40 min. The cefuroxime group had a significantly lower rate of bacteraemia (33%) compared with the control group (86%). The predominant bacteria were gram-positive cocci. Fifty four different strains of bacteria were isolated, of which most were susceptible to cefuroxime. However seven strains which were susceptible to cefuroxime in vitro, were isolated from blood cultures of the treated group. Serum concentrations of cefuroxime ranged from 52.3 to 141.6 mg/l at 10 min and 32.6 to 91.8 mg/l at 40 min with a mean of 78.6 and 55.1 mg/l respectively. The only other factor which had a significant influence on the rate of bacteraemia was the number of extracted teeth. Oral hygiene and periodontal status did not significantly affect bacteraemia. There were no wound infections in any of the groups. During these dental interventions, sufficient plasma levels of antibiotic prevented bacteraemia. Selected patients might benefit from single-dose-prophylaxis with cefuroxime in preparation for dental surgery.

Adult↗
PubMed1999

Experiences with cranial neuronavigation in pediatric neurosurgery.

Frameless, infrared-based neuronavigation (Surgical Microscope Navigator and Surgical Tool Navigator) was applied to intracranial neurosurgery in 22 children and infants (age range 7 months to 16 years). Predominant diagnoses were tumor and hydrocephalus (including multiloculated forms); the surgical procedures were open microneurosurgery in 10 cases and neuroendoscopy in 12 patients. There were no principal technical problems even in very young infants. Surgical and clinical results were satisfying in all cases. Neuronavigation proved to be particularly helpful in targeting deep-seated processes and in guiding neuroendoscopy in cases of multiloculated hydrocephalus or small ventricles.

Adolescent↗
PubMed1999

High cure rates and reduced long-term toxicity in pediatric Hodgkin's disease: the German-Austrian multicenter trial DAL-HD-90. The German-Austrian Pediatric Hodgkin's Disease Study Group.

PURPOSE: To further reduce therapy-related late effects in patients with pediatric Hodgkin's disease (HD) while maintaining the high cure rates achieved with vincristine, prednisone, procarbazine, and doxorubicin (OPPA) or OPPA/cyclophosphamide, vincristine, prednisone, and procarbazine (COPP) chemotherapy and involved-field radiotherapy. The risk of testicular dysfunction was addressed by substituting etoposide for procarbazine (OEPA) in the induction therapy for boys. Radiation doses and fields were further reduced. PATIENTS AND METHODS: Three hundred nineteen boys and 259 girls younger than 18 years with previously untreated HD, enrolled onto the study between 1990 and 1995, were allocated to treatment group (TG)1 (early stages), TG2 (intermediate stages), or TG3 (advanced stages). All groups underwent two cycles of OEPA (boys) or OPPA (girls) for induction chemotherapy. TG2 and TG3 continued on additional two or four cycles, respectively, of COPP. Low-dose radiotherapy was given to the initially involved sites, ie, reduced involved fields. RESULTS: Initial response to OPPA or OEPA induction was virtually identical. Eight of 578 patients experienced early progression of HD. Thirty-seven relapses, three secondary tumors, and no secondary leukemias have been recorded, with a median follow-up duration of 5.1 years (maximum, 8.1 years). Thirteen of 578 patients died. The probability of 5-year event-free survival/overall survival is 91%/98% in the total group, 94%/97% with OPPA, and 89%/98% with OEPA induction therapy. Risk factor analysis showed two significant prognostic factors: histologic subtype NS2 and "B" symptoms. OEPA induction therapy, large mediastinal tumor, and age were not significant. Preliminary studies of testicular function indicate a lower risk of germ cell damage than previously documented with OPPA. CONCLUSION: OEPA is a satisfactory alternative to OPPA. Radiotherapy can be confined to involved sites when combined with appropriate chemotherapy. The DAL-HD-90 regimen represents a comprehensive treatment program for all stages of pediatric HD and offers a favorable benefit/risk ratio, combining excellent disease control, moderate acute toxicity, and reduced long-term toxicity.

Adolescent↗
PubMed1999

Impact of preoperative bimodality induction including twice-daily radiation on tumor regression and survival in stage III non-small-cell lung cancer.

PURPOSE: The objective of this prospective study was to assess the feasibility, toxicity, and efficacy of an intensive trimodality approach in stage III non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Fifty-four patients with NSCLC and biopsy-proven N2 nodes (IIIA; n = 25) or N3 nodes or T4 lesions (IIIB; n = 29) were administered two initial cycles of ifosfamide, carboplatin, and etoposide; subsequent radiotherapy (45 Gy, twice-daily 1.5 Gy) with concurrent carboplatin and vindesine; and surgery if the patient's disease was resectable or conventional radiotherapy (16 Gy, 2 Gy/d) if the patient's disease was not resectable or incompletely resectable. RESULTS: Thirty-seven patients (69%) responded to preoperative induction. Forty of 54 patients (74%) had disease that was resectable, with 34 (63%) complete resections (R0). A substantial pathologic response (tumor regression [TR] > 90%) was achieved in 27 of 54 patients (50%) and is revealed as an independent predictor for long-term survival after surgery. Five treatment-related deaths (9%) occurred. With a median follow-up period of 44 months, calculated survival rates at 3 years were 35% for patients with stage IIIA disease, 26% for patients with stage IIIB disease, and 56% for patients with R0 disease and TR > 90%. CONCLUSION: This trimodality approach is feasible and results in encouraging 3-year survival rates in prognostically unfavorable patients with stage III NSCLC. Patients experiencing a 90% degree of pathologic TR were most likely to achieve long-term survival.

Adult↗
PubMed1999

Acoustic airway profiles in unilateral cleft palate patients.

OBJECTIVE: This study investigates the nasal airway in unilateral cleft palate patients by means of a noninvasive, objective diagnostic method that provides topographic information about the airway profile. DESIGN: A consecutive sample of patients was measured. SETTING: Cleft palate rehabilitation center of the University of Mainz, Germany. PATIENTS: Forty-nine subjects were investigated: 34 full-grown patients with complete unilateral cleft lip and palate and 15 controls with subjective normal nasal patency. INTERVENTION: A transnasal series of three acoustic measurements of nasal volume was performed per nostril; measurements were taken both before and after decongestion with 0.3 mg xylometazoline per nostril. Minimum cross-sectional area, nasal volume, and decongestion capacity were calculated for both the cleft side and the contralateral side and for both nasal sides in controls. RESULTS: Pathologic obstructions (<0.4 cm2) were detected on the cleft side in 75% of patients but were detected in only 15% of patients on the contralateral side (p < .001). The valve area of the cleft side (0.32 +/- 0.2 cm2) yielded significantly (p < .001) lower cross-sectional values compared with the contralateral side (0.56 +/- 0.1 cm2). Total nasal volume was determined to be 35% smaller on the cleft side (p < .001). Significantly higher decongestion capacity was verified on the cleft side, thus indicating mucosal hypertrophy. CONCLUSION: Despite a wide range of interindividual variability, we recognized a characteristic "descending W"" airway pattern in cleft palate patients. Acoustic rhinometry seems to be a powerful tool for acquiring topographic information about the individual airway profile. It has proven helpful in visualizing the location and amount of pathologic obstructions, rendering it especially useful for preoperative investigation and quality control in corrective cleft nose surgery.

Acoustics↗
PubMed1999

Monitoring noise susceptibility: sensitivity of otoacoustic emissions and subjective audiometry.

The capacity of different audiological methods to detect a high noise susceptibility was examined in 20 normally hearing and 26 especially noise-susceptible subjects. The latter were selected from 422 soldiers in field studies: they had shown a temporary threshold shift (TTS) in pure tone audiometry (PTA) after regular training with firearms. In laboratory experiments, the TTS-positive soldiers were re-examined using greatly reduced sound intensities, which caused no TTS in a control subject group. Before and after acoustic stimulation, different subjective (PTA, high frequency audiometry (HFA), upper limit of hearing (ULH)) and objective (transiently evoked otoacoustic emissions (TEOAE), distortion products (DPOAE)) audiological tests were performed. After exposure to low impact noise in the laboratory, in both PTA and HFA, a TTS was observed in 11.5% (N = 3) of the noise-susceptible group (compared to 0% in the control group). In the TTS-positive group, deterioration of the ULH occurred in 28% (N = 7) (compared to 15% (N = 3) in the control group). An ULH improvement occurred in only one subject (3.8%) (compared to 25% (N = 5) in the control group). Significant alterations of click-evoked OAE-amplitudes were found in 26.9% (N = 7) of the selected groups, whereas stable emissions were observed in all but one subject (5%) of the control group. However, DPOAE alterations were seen in 19.2% (N = 5) of the TTS-positive soldiers but also in 25% (N = 5) of the control group. These results suggest that TEOAE provides a more sensitive and more objective method of detecting a subtle noise-induced disturbance of cochlear function than do PTA or DPOAE.

Adolescent↗
PubMed1999

Comparison of 3,000 IU aXa of the low molecular weight heparin certoparin with 5,000 IU aXa in prevention of deep vein thrombosis after total hip replacement. German Thrombosis Study Group.

BACKGROUND: The aim of this randomized, double-blind and prospective clinical trial was to investigate whether an increase of the conventional daily dosage (3,000 IU aXa) of the low molecular weight heparin certoparin up to 5,000 IU aXa/day might lower the incidence of deep vein thrombosis (DVT) in patients undergoing elective hip surgery. METHODS: The main criterium of this trial was the incidence of DVT diagnosed by bilateral ascending venography, which was performed either if DVT was clinically suspected or in each remaining patient between the 12th and the 14th postoperative day. A total number of 172 patients were enrolled to receive the conventional dosage of 3,000 IU aXa (Mono-Embolex NM) and 169 patients to receive the high dosage form (5,000 IU aXa) once daily. The mean age (+/-SD) was 69.6+/-9.5 and 67+/-11.7 years. RESULTS: No relevant differences were found concerning predisposing risk factors. The duration of surgery was 93+/-25.2 and 88+/-21.4 min (mean+/-SD). Surgical type and approach were not different between the groups. Deep vein thrombosis was detected in 17 patients (9.9%) in the conventional dose group and in 16 patients (9.5%) in the high dose group (intent-to-treat analysis; n.s.). The rate of bleeding complications was not significantly different except the cell saver volumes (770+/-136 vs 475+/-186 ml; p<0.001). No significant difference was found in the serious adverse event reporting along the lines of EC-GCP (10 vs 8 events; p=0.65). CONCLUSIONS: This clinical trial confirmed that the conventional dosage (3,000 IU aXa/day) of certoparin ensures maximal antithrombotic activity.

Adult↗
PubMed1999

Amifostine--a radioprotector in locally advanced head and neck tumors.

PURPOSE: There are some preliminary informations about the beneficial use of amifostine in avoiding side effects in patients with head and neck tumors who underwent radiotherapy. PATIENTS AND METHOD: Amifostine was given as daily intravenous application (500 mg) 10 to 15 minutes prior to radiotherapy in 20 patients. The results were compared with another collective of patients which was similar. RESULTS: According to the WHO score mucositis became manifest in 10 patients (Grade I) and 4 patients (Grade II) in the amifostine group vs 9 patients (Grade II), 6 patients (Grade III) and 1 patient (Grade IV) in the control group. Xerostomia has been seen in 15 patients (Grade I) and 5 patients (Grade II) after administration of amifostine. Without the drug 2 patients suffered from xerostomia (Grade I), 8 patients (Grade II) and 8 patients (Grade III), respectively. Administering amifostine had been feasible and non problematic. Only a small rate of toxic side effects like nausea (11%) or emesis (4%) was documented. CONCLUSIONS: Amifostine is an effective radioprotector decreasing acute and late side effects in patients with head and neck tumors.

Adult↗
PubMed1998

Preoperative assessment of airway patency in the planning of corrective cleft nose surgery.

OBJECTIVE: To investigate acoustic assessment of complex structural anomalies in cleft lip and palate associated nasal deformities and its impact on the planning of corrective rhinosurgery. PATIENTS: Twenty-three consecutive patients with unilateral CL(P) during routine consultations, three of them prior to corrective surgery. INTERVENTION: Acoustic measurements of the nasal airway crosssectional area were obtained for both nasal cavities. The size of isthmus area and isthmus location as well as the nasal volume and decongestion capacity in various regions of interest were determined. RESULTS: Obstructions in the area of the nasal valve (< 0.4 cm2) were detected in 85% of the patients on the cleft side, but only 15% on the contralateral side. Severe mucosal hypertrophy was a common finding on the cleft side with a significantly higher capacity of decongestion, especially in the posterior region of the nasal cavity (P < 0.02). A second stenosis located behind the physiological isthmus was found in 16 patients. CONCLUSION: Acoustic rhinometry is a noninvasive, objective method. It measures the degree and the exact location of airway obstructions. Apart from the equipment, the only prerequisite is a cooperative patient. The measurement has direct therapeutic consequences. If the exact cause and location of airway stenosis are known, it is easier to adapt the corrective surgical procedures to suit the individual patient. The decision in favour of additional therapeutic measures can be made on a more rational basis to prevent residual airway problems postoperatively. Preoperative acoustic rhinometry offers valuable information concerning the severity and location of nasal airway obstructions and thus proves to be a helpful tool in the planning of corrective operative measures.

Acoustics↗
PubMed1998

Objective evaluation of velopharyngeal function by acoustic reflection measurements.

OBJECTIVE: To investigate whether acoustic pharyngometry is capable of discriminating velopharyngeal mobility in cleft and non-cleft subjects by determination of epipharyngeal volume changes with active muscle function. DESIGN: Case control study, consecutive sample. SETTING: Cleft palate rehabilitation centre. PATIENTS: Thirty-three consecutive cleft palate patients, among them 10 following pharyngeal flap surgery and 32 controls without velopharyngeal pathology. INTERVENTION: Transnasal acoustic measurements of airway cross-sectional area in the state of relaxed and tensed pharyngeal muscles. Determination of epipharyngeal volume changes by integrating the difference of the airway profile from the choane for a distance of 5 cm (EV0-5). Measurements of defined changes in the epipharynx served as reference. RESULTS: Acoustic pharyngometry is capable of discriminating (P < 0.05: U test, Mann-Whitney) the volume effect of velopharyngeal mobility in CP patients (6.5 cm3) from the control group (8.0 cm3). A 'pharyngeal flap type' and a 'non-pharyngeal flap type' of restriction was observed. The individual effect of velopharyngoplasty on pharyngeal mobility can thus be determined. CONCLUSION: Acoustic pharyngometry is a non-invasive, quantitative investigation technique which seems well suited for the evaluation of velopharyngeal mobility. We expect it to be a helpful tool in objectively monitoring the effect of therapeutic intervention on velopharyngeal mobility, and it may provide a better understanding of the pattern of movement in CP patients.

Acoustics↗
PubMed1998

[Fetal surgery in the head-neck area. Current status and new possibilities with the endoscope].

Fetal surgery is defined as the intrauterine surgical correction of malformations that endanger the unborn child's life in prenatal stages of development or lead to death or severe damage of the child postnatally. Such surgery is a clinical reality now. Indications for intrataurine surgical procedures also exist for head and neck abnormalities, especially in the upper respiratory tract. These include exposure and temporary obstruction of the fetal trachea for correction of pulmonary hypoplasia in cases with congenital diaphragmatic hernias, prenatal tracheotomy in cases of laryngeal atresia for the correction of lethal pulmonary overdistension, and resection of embryonic tumors that obstruct the respiratory tract. The relatively high surgical risk resulting in particular from preterm labor occurring postoperatively may be reduced by employing minimally invasive techniques. Endoscopic procedures render opening of the uterus unnecessary and are of particular importance. In part of the procedures, only endoscopic surgery has led to therapeutic success rates justifying its clinical use. Further reduction of the operative risk suggests prenatal interventions, even in cases with non-lethal conditions. More diseases of the head and neck may thus be included in the spectrum of indications. One example is prenatal correction of a cleft lip and palate, which until now has only been performed in animal experiments. The particular characteristics of fetal wound healing allow this to take place without scarring up to a certain stage in pregnancy. This offers the prospect of a surgical correction that is invisible externally and avoids growth-impeding scars. The particular ethical and legal aspects of fetal surgery are discussed.

Congenital Abnormalities↗
PubMed1998

Histotomography of the odontoblast processes at the dentine-enamel junction of permanent healthy human teeth in the confocal laser scanning microscope.

The translucency of teeth allows the non-destructive subsurface visualisation of their microstructure by confocal laser scanning microscopy (CLSM) at a level of about 150 microns below the surface. The dentine-enamel junction (DEJ) is accessible only directly adjacent to the cervix of the tooth. Therefore teeth have to be sectioned for studying marginal areas of the dental hard tissue. The potential of the technique for (pseudo) three-dimensional visualisation allows the study of an array of individual confocal images, the interpretation of which is similar to that of macroscopic tomographs (CT-scan, MRI). Additionally, the extended focus mode yields the overlay of individual confocal images in the form of a two-dimensional projection. This mode of operation proved to be particularly suited for the visualisation of odontoblast processes in their whole extension. The three-dimensional junction between enamel and dentine, the branches of the odontoblast processes and their interactions with the DEJ is demonstrable by CLSM without staining or other procedures of sample preparation. The direct microscopic comparison between samples, either fresh or kept in a humid chamber, and Technovit-embedded sample blocks gives evidence that the risk of artefacts by sample storage or by the embedding procedure is minimal. The tomographs limited to subsurface areas of the tissue also exclude mechanical surface artefacts due to grinding or cutting.

Dental Enamel↗
PubMed1998

Treatment of injuries to the inferior alveolar nerve after endodontic procedures.

Overextension of filling material into the mandibular canal after root treatment in the lower jaw is a rare but serious complication. Mechanical compression, chemical neurotoxicity and local infection may cause irreversible nerve damage. A report on 11 patients with neurological complaints of the inferior alveolar nerve after endodontic treatment is summarised. The neurological findings are dominated by hypaesthesia and dysaesthesia. Half of the patients reported pain. Hyperaesthesia is found much more rarely. Nearly all the patients had a combination of one or more symptoms. Initial X-rays showed root filling material in the area of the mandibular canal. Nine cases were treated with apicectomy and decompression of the nerve; in two cases, extraction of the tooth was necessary. Only one patient reported persistent pain after surgery. If neurological complaints appear after root filling in the lower jaw, a nerve injury due to root filling material should be ruled out. In cases of overfilling, immediate apicectomy and decompression of the nerve with conservation of the tooth is often the treatment of choice; the tooth may be preserved and the best chance of avoiding permanent nerve damage is provided.

Adult↗
PubMed1998

[Histotomography studies of direct radiogenic dental enamel changes].

OBJECTIVE: The volume of literature on radiation-induced caries is still inconsistent as regards the state of the art. Our histotomographic studies have shown direct radiogenic effects on the dentoenamel junction (atrophy of the odontoblast processes). Whether there are direct effects of radiation on dental enamel is not yet known. MATERIAL AND METHOD: Sound teeth (group 1, n = 10) were compared either with enamel specimens after high dose in vitro radiation (500-2500 Gy; group 2; n = 10) and after experimental enoral in situ irradiation (60 Gy; group 3; n = 20), or with teeth from patients after cancer radiotherapy (36 Gy; group 4; n = 20) and with teeth which had obviously decayed due to cancer radiotherapy (60 Gy; group 5; n = 20). Vestibular enamel surfaces of the teeth were exposed to identical in vitro demineralizations (lactic acid gel; pH = 5.0). Each of the samples was prospectively studied histologically by confocal laser scanning microscopy (CLSM) after 90, 180 and 270 min of acid interaction. Data were interpreted micromorphometrically (width of the demineralized area) and micromorphologically. RESULTS: The width of the demineralized area varies between the two in vivo irradiated groups of specimens (group 4: P < 0.01; group 5: P < 0.001) and the high dose in vitro irradiated teeth (P < 0.01) and is significantly different from the sound controls. The histological image of the demineralization in subsurface areas in the teeth of radiotherapy patients is characterized by a total loss of the prismatic structure (homogeneously, amorphous substance). CONCLUSIONS: Direct radiogenic effects at the dentoenamel junction have been described earlier. The additional information offered by this study is that there are significant micromorphometric differences in the demineralizing behaviour of irradiated enamel. Obviously, enamel is less resistant to acid attack after irradiation.

Cobalt Radioisotopes↗
PubMed1998

[Confocal laser scanning microscopy (CLSM) for validation of non-destructive histotomography of healthy bone tissue].

OBJECTIVES: Fixation (formalin), decalcification (sections) or mechanical treatment (grinding) all bear the risk of artifacts occurring during hard-tissue histology. Because studies on the etiology of pathological changes mostly focus on subclinical lesions, artifacts can simulate early changes or even be superimposed on existing changes. The objective of this study was to determine how artifacts can be reduced. MATERIAL AND METHODS: In confocal laser scanning microscopy (CLSM) a focused laser beam scans the surface of the specimens and penetrates into the tissue. The intensity of the remitted light is recorded. The confocal effect is due to an extremely small aperture (pin-hole), excluding light from out-of-focus planes of the sample. By stepwise movement of the object table, a tomographic series of tomographic images is obtained. Sound cortical bone samples of the lower jaw (n = 20) were studied by light microscopy and by CLSM, visualizing identical areas of a ground sectioned sample after H&E staining. Additionally, embedded and fresh blocks of tissue of the same bone sample were studied histotomographically in the CLSM. RESULTS: (1) Light microscopic micromorphology of cortical bone can be visualized adequately in the CLSM; (2) many structures that can be visualized by light microscopy only after special staining (e.g., osteozyte processes) can be visualized by the CLSM using sample blocks without pretreatment. CONCLUSION: (1) Nondestructive subsurface histotomography by CLSM totally excludes mechanical artifacts; (2) physicochemical artifacts can be handled more easily because fresh samples can be studied; (3) pseudo-three-dimensional imaging allows histological interpretation of the tissue that is equivalent to macroscopic tomographic techniques (CT, MRT).

Artifacts↗
PubMed1998

[Value of (F18)-2-fluorodeoxyglucose PET scanning in staging mouth cavity carcinoma. Comparative evaluation of PET findings before and after preoperative radiochemotherapy with histological and computerized tomography findings].

OBJECTIVE: The lack of sensitivity and specificity of conventional imaging techniques based on morphological critera is responsible for considerable limitations in the staging and surveillance of oral cancer. Therefore, this study investigates the contribution of [F18]-2-fluordesoxyglucose (FDG) positron emission tomography (PET) to tumor management with special regard to lymphnode involvement and therapeutic monitoring after radiotherapy. DESIGN: Prospective observational study. PATIENTS: Twenty-one patients with advanced oral cancer, predominantly T3/T4. INTERVENTION: FDG-PET scans before and after preoperative radio(chemo)therapy. Standardized uptake values (SUV) were determined for the tumor site and lymphnode areas. PET scans were correlated to histological findings after ablative tumor surgery. RESULTS: FDG-PET yielded superior sensitivity and specificity for tumor and lymphnode assessment. The effect of radiotherapy was reflected by the metabolic activity of the tumor, which shows a close correlation between the decrease of FDG uptake and histologic tumor regression. PET detected distant metastases and simultaneous tumors. CONCLUSION: FDG-PET is a challenging imaging technique with the potential to improve staging procedures for oral cancer. In the monitoring of metabolic activity of the tumor in the course of radio(chemo)therapy, FDG-PET allows objective measurement of the treatment response.

Aged↗