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Biomedical subjects

W Wagner

Publications and source records attributed to W Wagner.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Patient satisfaction with dental implants].

BACKGROUND: Almost all implant systems available today achieve success rates of over 90%. The subjective satisfaction of patients with dental implants is only rarely considered in the definition of implant success and there are only limited data on the satisfaction of patients with dental implants in the literature. Therefore, a satisfaction analysis was carried out in a retrospective study. DESIGN OF STUDY: In addition to a clinical investigation, 330 patients with 1,273 implants (Astra, Frialit-2, IMZ TwinPlus and ITI) were asked to answer a standardized questionnaire to rate their personal opinion on the implant success. A total of 199 questionnaires (803 implants, 63%) were returned and could be analyzed. RESULTS: Of the patients, 67% participated in regular follow-up after implantation and 15% indicated postoperative discomfort. Patient satisfaction with the implants (rated on a scale of 1-6) was good or excellent (2 and 1, respectively) in 88% of cases. Satisfaction with the prosthetic treatment was 80%. The whole treatment was considered good or very comfortable by 86% of patients. If necessary, 91% of patients who underwent the procedure would do so again, and 94% would recommend the procedure to someone else. The Spearman correlation analysis did not reveal any statistically significant correlations between the clinical parameters and patient satisfaction scores. DISCUSSION: Despite the high number of patients involved ( n=330), the expected influence of objective clinical parameters on patient satisfaction could not be statistically evaluated. Nevertheless, in addition to the clinical parameters, subjective patient satisfaction should be included in the evaluation of implant success.

Dental Implants↗
PubMed2002

Disabling disturbance of olfaction in a dental technician following exposure to methyl methacrylate.

It is often difficult to diagnose dysosmia due to occupational olfactotoxic substances. The authors present a case of disabling disturbance of olfaction in a dental technician. This is very likely to have been caused by exposure to methyl methacrylate. From 1988-1992, the dental technician had very extensive and sustained contact with a self-polymerizing acrylic resin based on methyl methacrylate. Her perception of smell was still normal in 1988, but it deteriorated up to 1992. The olfactory disorders have persisted and impede social life and occupational rehabilitation.

Dental Technicians↗
PubMed2002

[Criteria of success in implantology].

BACKGROUND: So far there is no generally accepted definition of success in the case of dental implants, although criteria differing from country to country have been proposed, which evaluate the success of implants with reference to clinical and X-ray control parameters. The aim of the study was to examine the five most frequently used sets of criteria suggested for determination of the success or otherwise of implants ( Albrektsson, Jahn, Buser, NIH conference, Naert) and ascertain their relative values. METHODS: In a clinical review, 508 implants (Astra, Frialit-2, IMZ TwinPlus and ITI) were examined and a subjective evaluation of them was made by the patients. Subsequently a statistical analysis was executed (in situ rate, Kaplan-Meier, success criteria). RESULTS: The average observation time of all implants included in the study was 3.5 years, and the in situ survival rate was 95%; Kaplan-Meier survival analysis revealed that the probability of survival after 6 years was 93%. Application of different criteria for success gave very different results (Albrektsson 88%, Naert 89%, NIH 85%, Buser 88%, Jahn and dacute;Hoedt 75%). DISCUSSION: The increasing importance of quality assurance in medicine makes it necessary to establish standards that will permit reliable comparative analysis of how successful implants are in the future.

Dental Implantation, Endosseous↗
PubMed2002

[Growth stimulation of human osteoblast-like cells by thrombocyte concentrates in vitro].

AIM OF THE STUDY: Thrombocytes contain different growth factors. Their potential use for increasing bone regeneration is currently under discussion. Basic data about the biologic effect of platelet concentrates (platelet-rich plasma, PRP) are still lacking. This study analyzes the in vitro effect of PRP on the proliferation rate of human osteoblast-like cells (OLC). MATERIAL AND METHOD: Human OLC were stimulated with thrombocytes in different dilutions (0-1,700,000 thrombocytes/microliter). Three days later a WST test (Roche Diagnostics) was performed to measure the mitochondrial syntheses and cellular proliferation rate. RESULTS: The proliferation rate of the OLC was (concentration-dependent) increased up to a certain plateau by adding thrombocytes. Further stimulation led to a slight decrease in the proliferation rate. The statistical analysis of the extinction measurements showed significant differences in the cell proliferation rates between mostly all thrombocyte concentration groups (p < 0.0001). Moreover, a statistically significant difference was evaluated for the time-dependent change in extinction (0-5 h) (p < 0.0001). CONCLUSION: This study shows that the proliferation rate of human OLC can be stimulated in vitro by concentration-dependent platelet concentrates. This in vitro result supports the currently discussed assumption that the clinical use of PRP might increase bone regeneration.

Bone Regeneration↗
PubMed2002

Fluvoxamine: safety profile in extensive post-marketing surveillance.

The safety profile of the selective serotonin reuptake inhibitor, fluvoxamine, has been assessed in clinical and post-marketing studies. Post-marketing surveillance provides the opportunity to assess a drug's safety in every day clinical conditions in a much greater patient population than in clinical trials and therefore serves as a useful tool to detect signals for adverse effects with an incidence of less than 1 : 10,000. The safety profile of fluvoxamine was evaluated based on data from 17 years of global post-marketing surveillance in an estimated 28 million patients exposed to fluvoxamine. A total of 6,658 adverse drug reaction reports received from world-wide sources were reviewed and analysed. Post-marketing surveillance data confirmed the favourable safety profile already observed in clinical and post-marketing studies. A remarkably low level of suicidality, switch to mania, and sexual dysfunction was found. Serotonin syndrome appeared to be a very rare complication of fluvoxamine treatment. No signals for drug interactions unknown so far were identified. Withdrawal symptoms were observed in everyday clinical conditions, which were generally mild and resolved spontaneously. However, no cases suggestive for drug dependence have been reported. In conclusion, the data presented underlined that fluvoxamine offers a safe and well-tolerated option in the treatment of depression and obsessive-compulsive disorder.

Antidepressive Agents, Second-Generation↗
PubMed2001

The number of intratumoral dendritic cells and zeta-chain expression in T cells as prognostic and survival biomarkers in patients with oral carcinoma.

BACKGROUND: Dendritic cells (DCs) are antigen-presenting cells with a unique ability to cross prime T cells and generate strong antitumor responses. This study evaluates the presence and prognostic significance of DCs as well as functional T cells, which accumulate in the microenvironment in patients with oral squamous cell carcinoma (OSCC). METHODS: Immunohistochemistry for S-100 positive or p55 positive DCs and for T-cell receptor (TcR)-associated zeta-chain expression in tumor-infiltrating lymphocytes (TILs) was performed in 132 paraffin embedded specimens from patients with primary OSCC. The median clinical follow-up for the patients was 50 months. The numbers of intratumoral DCs or TILs expressing the zeta chain were determined microscopically and compared with clinical and pathohistologic prognostic parameters, including disease stage, T stage or tumor grade, lymph node involvement, as well as disease free survival and overall survival. RESULTS: Immunostaining identified DCs in the epithelial compartment of the tumors (S-100 positive) as well as interdigitating reticular DCs (p55 positive) in peritumoral areas. Based on S-100 staining, intratumoral DC infiltrates were low (<10 DCs per high-power field [HPF]) in 20% of OSCC specimens, intermediate (10-20 DCs per HPF) in 42% of OSCC specimens, and high (>20 DCs per HPF) in 37% of OSCC specimens. The number of S-100 positive DCs was positively and significantly correlated with that of p55 and of TILs with normal zeta-chain expression. A low number of infiltrating S-100 positive DCs was more predictive of poor survival (hazard ratio, 7.95) than lymph node involvement (hazard ratio, 3.36) or late T stage (hazard ratio, 2.92). A significant but weaker association of p55 positive DC infiltration with survival was observed. Low density of DCs and low or absent expression of the zeta chain in TILs correlated with each other and predicted the poorest survival and the greatest risk. CONCLUSIONS: The number of DCs infiltrating the tumor is a highly significant prognostic parameter in patients with OSCC. Furthermore, the absence or paucity of DCs is strongly linked to abnormalities in the TcR-associated zeta chain in TILs. The two biomarkers, zeta-chain expression in TILs and the number of S-100+ DCs in the tumor, independently predict overall survival, disease free survival, and time to disease recurrence in patients with OSCC.

Adult↗
PubMed2001

Angiotensin II-induced stimulation of p21-activated kinase and c-Jun NH2-terminal kinase is mediated by Rac1 and Nck.

p21-activated kinase (PAK) has been shown to be an upstream mediator of JNK in angiotensin II (AngII) signaling. Little is known regarding other signaling molecules involved in activation of PAK and JNK by AngII. Rho family GTPases Rac and Cdc42 have been shown to enhance PAK activity by binding to p21-binding domain of PAK (PAK-PBD). In vascular smooth muscle cells (VSMC) AngII stimulated Rac1 binding to GST-PAK-PBD fusion protein. Pretreatment of VSMC by genistein inhibited AngII-induced Rac1 activation, whereas Src inhibitor PP1 had no effect. Inhibition of protein kinase C by phorbol 12,13-dibutyrate pretreatment also decreased AngII-mediated activation of Rac1. The adaptor molecule Nck has been shown previously to mediate PAK activation by facilitating translocation of PAK to the plasma membrane. In VSMC AngII stimulated translocation of Nck and PAK to the membrane fraction. Overexpression of dominant-negative Nck in Chinese hamster ovary (CHO) cells, stably expressing the AngII type I receptor (CHO-AT1), inhibited both PAK and JNK activation by AngII, whereas it did not affect ERK1/2. Finally, dominant-negative Nck inhibited AngII-induced DNA synthesis in CHO-AT1 cells. Our data provide evidence for Rac1 and Nck as upstream mediators of PAK and JNK in AngII signaling and implicate JNK in AngII-induced growth responses.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Ypt protein prenylation depends on the interplay among levels of Rab escort protein and geranylgeranyl diphosphate in yeast cells.

Farnesyl diphosphate (FPP), an intermediate of the sterol biosynthetic pathway, is used by farnesyl transferase to farnesylate, among others, the Ras proteins, and by geranylgeranyl diphosphate synthase to produce geranylgeranyl diphosphate (GGPP). GGPP is then transferred by geranylgeranyl transferase II (GGTase II) to Rab/Ypt members of the Ras superfamily known to be required at all stages of vesicle transport in both mammals and yeast. Formation of a complex between a Rab/Ypt protein and an accessory protein named the Rab escort protein (REP) is a prerequisite for GGTase II substrate recognition. Little is known about the factors that regulate GGTase II activity in living cells but, based on available data, it seems possible that vesicle transport in higher eukaryotes is regulated by the levels of prenylated Rab/Ypt proteins in the cells. Here we show that the levels of REP play an important role in regulating GGTase II activity in yeast cells if sufficient substrates are present. Moreover, overexpression of REP causes, directly or indirectly, an increased level of Ypt substrates available for prenylation, which in turn leads to the depletion of the GGPP pool in the cell. Overall our data suggest that the levels of REP and the availability of GGPP play a role in regulating Ypt protein prenylation.

Alkyl and Aryl Transferases↗
PubMed2001

[Chronic radiation effects on dental hard tissue (radiation caries). Classification and therapeutic strategies].

OBJECTIVES: Since the first description of rapid destruction of dental hard tissues following head and neck radiotherapy 80 years ago, "radiation caries" is an established clinical finding. The internationally accepted clinical evaluation score RTOG/EORTC however is lacking a classification of this frequent radiogenic alteration. MATERIAL AND METHODS: Medical records, data and images of radiation effects on the teeth of more than 1,500 patients, who underwent periradiotherapeutic care, were analyzed. Macroscopic alterations regarding the grade of late lesions of tooth crowns were used for a classification into 4 grades according to the RTOG/EORTC guidelines. RESULTS: No early radiation effects were found by macroscopic inspection. In the first 90 days following radiotherapy 1/3 of the patients complained of reversible hypersensitivity, which may be related to a temporary hyperemia of the pulp. It was possible to classify radiation caries as a late radiation effect on a graded scale as known from RTOG/EORTC for other organ systems. This is a prerequisite for the integration of radiation caries into the international nomenclature of the RTOG/EORTC classification. CONCLUSIONS: The documentation of early radiation effects on dental hard tissues seems to be neglectable. On the other hand the documentation of Late radiation effects has a high clinical impact. The identification of an initial lesion at the high-risk areas of the neck and incisal part of the tooth can lead to a successful therapy as a major prerequisite for orofacial rehabilitation. An internationally standardized documentation is a basis for the evaluation of the side effects of radiooncotic therapy as well as the effectiveness of protective and supportive procedures.

Adult↗
PubMed2001

[Therapy monitoring with 2-(18F)-FDG positron emission tomography after neoadjuvant radiation treatment of mouth carcinoma].

BACKGROUND: Combined protocols of radiation therapy and surgical resection, as applied in advanced oral cancer, rely on objective and early assessment of treatment response to radiation therapy. Non-responders require immediate radical salvage surgery even in spite of substantial operative risks, while complete or subtotal response may give reasons for continuing the conservative approach. Therefore, we investigated radiation response by FDG-PET for early monitoring of oral cancer. PATIENTS AND METHODS: In 30 patients with advanced stages of oral cancer (Table 1), FDG-PET (Siemens, ECAT EXACT 922) was performed within 4 weeks after completion of preoperative radiation therapy (36 Gy). SUV of tumor regions were compared to the histologic degree of tumor regression in complete resection specimens. Statistic evaluation included correlation analysis of SUV vs tumor regression and ROC analysis for SUV cut-off values. RESULTS: While low FDG accumulation was found in tumors with histological complete remission (2.3 +/- 0.4) as well as in cases of residual tumor (3.4 +/- 1.8), high FDG uptake was a rather specific indicator of vital tumor tissue (Figure 2). Significant correlation (p = 0.045) between postradiotherapeutic FDG-uptake and histological tumor regression was recognized. A SUV > 2.75 as a clinically practicable threshold value for the identification of residual vital tumor resulted in a specificity of 88%, sensitivity of 68%, a positive predictive value of 94% and a negative predictive value of 50% (Figure 3). Based on our actual follow-up data we could not confirm a significant correlation between postradiotherapeutic SUV and patients' survival. CONCLUSION: Within a standardized protocol, FDG-PET recognize treatment response to radiation therapy in oral squamous cell carcinoma with a reasonable specificity and thus provides a basis for further therapeutic decisions. An increased SUV (> 2.75) may be the rational to justify an aggressive surgical approach even when patients face substantial surgical or anesthesiological risk. However, the posttherapeutic pattern of glucose uptake varies with the applied treatment modalities and has to be explored for the protocol applied.

Adult↗
PubMed2001

[The value of qualitative regression grading as a prognostic factor for survival after preoperative radiochemotherapy in patients with advanced head and neck cancer].

BACKGROUND: Multimodal therapeutic strategies gain importance in locally advanced squamous cell carcinoma of the head and neck. Quantitative regression grading can be traced as an independent prognostic parameter in the histological examination in many neoadjuvantly treated cancers. Various regression systems have been suggested. We propose an easy to apply and economical score that seems to have a significant prognostic value in squamous cell carcinoma of the head and neck. PATIENTS AND METHODS: 43 patients with Stage IV squamous cell carcinoma of the head and neck have been treated neoadjuvantly with two cycles chemotherapy (ifosfamide 1.5 g/m2 day 1-5 with mesna [300 mg/m2], cisplatin 60 mg/m2 day 5, second cycle day 22). Hyperfractionated accelerated radiotherapy (30 Gy) was given from day 29 on. We divided the resected tumors histologically as follows: Grade I--no tumor cells to be identified, Grade II--necrosis, Grade III--partial destruction of the carcinoma, Grade IV--vital carcinoma. RESULTS: After 1 year the overall survival amounted to 79%, after 2 years 56%. A significant correlation could be established between qualitative tumor regression and survival. The 1-year survival depended on the regression of the primary as follows: 94% in Grade I, 80% in Grade II, 60% in Grade III and 56% in Grade IV. For the 2-year survival: 76%, 40%, 40%, 11% (p < 0.01). The results were similar regarding the neck dissections. CONCLUSIONS: After radiochemotherapy the histological regression is a significant prognostic factor of survival. A simple system with four subgroups is suggested which seems to be of a high prognostic value. We discuss to intensify the treatment for patients with good regression after neoadjuvant therapy for a further reduction of recurrence.

Adult↗
PubMed2001

[IMZ-TwinPlus bone implant system--4 years clinical experience].

AIM OF THE STUDY: For more than twenty years the IMZ-system has been in clinical use, since 1995 modified as IMZ-TwinPlus. The aim of this prospective clinical trial was to analyse the success of the latter implant system, which is an automatically threading cylindrical titanium screw with a deep structured surface (Fa. FRIATEC AG, Mannheim, BRD). Investigated parameters were the peri-implant situation of the soft tissues, the bone loss and the rate of implant failure after a maximum period of 4.5 years of clinical use. MATERIAL AND METHODS: From 1995-2000 sixty-eight patients were provided with a total of 278 IMZ TwinPlus screw implants for various indications (mainly alveolar ridge atrophy). 191 implants were inserted without any, 35 implants with a loco-regional and another 52 implants after comprehensive reconstructive osteoplastic surgery. 38 patients with 155 implants were re-examined using a standardised protocol to evaluate peri-implant hard- and soft tissue situation as well as the patient's subjective assessment of the treatment. RESULTS: With a maximum of 54 months the mean observation period was 30 months. The implant failure rate has risen to 6% so far (n = 18 in 12 patients). Two patients bearing 7 implants have passed away. One patient with 4 implants was lost to follow up. 249 implants were still under function at examination, thus the in situ rate was 91%. The Kaplan-Meier survival rate after 54 months proved 91%. DISCUSSION: To our knowledge there are at present no other data published on the survival rate of the IMZ TwinPlus implant system. The results of this study evaluate a survival rate similar to the classical IMZ cylinder implant and other implant systems for the analysed observation period. CONCLUSIONS: After a maximum observation period of 4.5 years the IMZ TwinPlus implant system showed results in the range of other well-established implant systems. Designed to resist rotation of the superstructure the IMZ TwinPlus screw implant widens the range of indications in comparison to the classical IMZ cylinder implant system.

Adult↗
PubMed2001

Prophylaxis of radiogenic sialadenitis and mucositis by coumarin/troxerutine in patients with head and neck cancer--a prospective,randomized, placebo-controlled, double-blind study.

OBJECTIVE: To study the efficacy of coumarin/troxerutine for the protection of salivary glands and mucosa during irradiation. DESIGN: Prospective, randomized, placebo-controlled, double-blind trial. SETTING: University hospital, Germany. PATIENTS: 48 patients who had radiotherapy to the head and neck. MAIN OUTCOME MEASURES: Salivary gland scintigraphy and acute side-effects of radiotherapy (Radiation Therapy Oncology Group (RTOG) score). RESULTS: 23 patients (11 experimental, 12 placebo) completed the study. The global efficacy measure combining scintigraphy and RTOG score favoured the experimental arm (P=0.07). The RTOG score showed significantly fewer acute side-effects of radiation in the experimental arm (P<0.05). CONCLUSION: The results suggest that coumarin/troxerutine have a favourable effect in the treatment of radiogenic sialadenitis and mucositis.

Adult↗