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J Schubert

Publications and source records attributed to J Schubert.

At least 37 records · Page 2Linked to original sources

Comparison of the bond strength of selected adhesive dental systems to cortical bone under in vitro conditions.

The study was performed to compare the tensile bond strength attained between composite and bone and between bone and bone using two different adhesive systems (Clearfil New Bond and Histoacryl) in vitro. Sixty porcine bone specimens with a total thickness of 4.0 mm (+/- 0.5 mm) and a cortical layer of 1.5 mm (+/- 0.2 mm) were obtained under standardised conditions. Ten specimens each were assigned to four experimental groups: group A: Clearfil New Bond (bone-composite); group B: Clearfil New Bond (bone-bone); group C: Histoacryl (bone-composite); group D: Histoacryl (bone-bone). The tensile bond strength of the adhesive agents mentioned above was measured 15 min after application and also after light-curing of the composite filling material (Tetric Ceram, colour A2; groups A and C) using a universal testing machine. The tensile bond strength measured was as follows: group A 8.00 MPa (+/- 1.36 MPa), group B 6.39 MPa (+/- 2.05 MPa), group C 5.22 MPa (+/- 1.96 MPa), and group D 1.95 MPa (+/- 0.49 MPa). Tensile bond strength was significantly increased in group A compared to groups C and D (P < 0.05, Tukey's test). The values in group D were significantly reduced compared to all other groups (P < 0.05, Tukey's test). Despite the limitations of an in vitro investigation, it can be concluded that adhesive systems might be a useful alternative in bone bonding. The use of dentin adhesives seemed to produce higher bond strength to bone than that attained with the cyanoacrylate adhesive.

Animals↗

New cut-off point between T1 and T2 renal cell carcinoma - necessary for a better discriminatory power of the TNM classification.

PURPOSE: We evaluated the pathological features of tumor size, lymph node and distant metastases, cell type, growth pattern, infiltration pattern, histological grade, local invasion and venous involvement of organ-confined renal carcinomas. The aim of this study was the re-evaluation of the TNM classification and the tumor cut-off point between T1 and T2 for renal cell carcinomas from the 1987 to the 1997 versions. MATERIALS AND METHODS: (1) Patients with renal cell carcinoma who had been operated between October 1992 and August 2001 were evaluated. 437 of 691 patients showed T1 and T2 tumors. These organ-confined tumors have been divided into five groups: group 1: tumor-size of 20 mm or less (n = 16), group 2: 21-30 mm (n = 79); group 3: 31-40 mm (n = 83; group 4: 41-70 mm (n = 184), and group 5: more than 70 mm in diameter (only T2, n = 75). Follow-up ranged from 0 to 100 months (average 28.63 months). (2) Of 15,347 autopsies performed in Jena between 1985 and 1996, 272 renal cell carcinomas were revealed. In 145 of these 272 cases renal cell carcinomas were limited to the kidney. These 145 tumors were divided accordingly into 5 groups: group 1: 20 mm or less (n = 33), group 2: 21- 30 mm (n = 31); group 3: 31-40 mm (n = 29); group 4: 41-70 mm (n = 42), and group 5: T2 (n = 10). Clinicopathological criteria examined were lymph node and distant metastases, cell type, growth pattern, infiltration pattern, histological grade, local invasion and venous involvement. To identify the optimal cut-off point between T1 and T2 disease the chi2 test was used. RESULTS: (1) In the clinical series only 1.8% (n = 8) of all cases showed lymph node metastases. Distant metastases were shown in 57 cases (13.04%); within group 1: 0%, group 2: 7.59%, group 3: 1.20%, group 4: 15.76%, group 5: 28%. The tumor grading was statistically correlated with tumor size. (2) In the pathological series 94 of the evaluated 145 patients were downstaged from T2(1987) to T1(1997). Lymph node and distant metastases were well correlated with tumor size. Lymph node metastases were seen in 0, 12.9, 31, 29.3 and 40% (group 1 to group 5) and distant metastases in 12.1, 25.8, 41.4, 47.7 and 60%. There were no statistically significant differences between T2(1997) and T1(3-7 cm). The tumor grading was statistically correlated with tumor size (grade 1: in 66.7, 25.8, 17.2, 9.5 and 0%). CONCLUSION: Our data suggest that the current cut-off diameter between T1 and T2 renal cell carcinomas (7 cm) is too high. Lowering the cut-off level will result in better discriminatory power of the TNM classification. From our data, we conclude that the cut-off diameter should be lowered to 3.5 cm (p < 0.001).

Adult↗

Integrated optical Mach-Zehnder modulator based on polycrystalline BaTiO3.

Good-quality polycrystalline BaTiO3 thin films are deposited on MgO substrates by pulsed laserdeposition. The deposition parameters are optimized to achieve optical-quality films with an attenuation coefficient of 4 dB/cm at the 633-nm wavelength. Thin-film electro-optic Mach-Zehnder modulators are fabricated with standard lithography and ion-beam etching. The waveguides patterned by lithography are the ridge type, and they ensure single-mode propagation in the wavelength range of 633-1550 nm. An electro-optic coefficient of 22 pm/V is estimated for the polycrystalline BaTiO3 films.

Journal Article↗

No influence of the P-glycoprotein genotype (MDR1 C3435T) on plasma levels of lopinavir and efavirenz during antiretroviral treatment.

BACKGROUND: In a retrospective study of HIV patients under antiretroviral therapy, we investigated the influence of the MDR1 genotype (C3435T) on plasma levels of lopinavir (LPV) and efavirenz (EFV). METHODS: The MDR1 genotype was analysed from 67 patients who were treated with LPV (n = 32; mean treatment period 53 weeks) and/or EFV (n = 43, mean treatment period 105 weeks) between 1999 and 2003. Plasma levels of LPV (trough levels) and EFV (12-h-levels) were determined every three months. Data were analysed by the Kruskal-Wallis test. RESULTS: There were no significant differences in the LPV and EFV plasma levels with respect to the MDR1 3435 genotype. CONCLUSIONS: We did not find evidence for an influence of the MDR1 3435 genotype on plasma levels of LPV and EFV.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Resolution of HCV infection in a HIV-infected patient under HAART after several hepatitis flare-ups.

Highly active antiretroviral therapy (HAART) has been shown to have a beneficial effect on several opportunistic and other coinfections of HIV infected individuals. The effect of HAART on HCV coinfections is controversial. We describe the case of a patient, in whom a close temporal relationship between changes in HIV viremia, HCV viremia and ALT levels was observed. Longterm suppression of HIV replication by HAART was associated with a normalization of ALT levels and finally clearance of the HCV infection. Our data suggest that improved immune functions due to reductions of the HIV load led to a better control and finally resolution of the HCV infection in this patient.

Acute Disease↗

[Temporomandibular function after malocclusion operations compared with a representative population group study].

AIM: The temporomandibular function of patients after orthognathic surgery was evaluated with the Helkimo index (D 0-III) and compared with a normal population. PATIENTS AND METHODS: Temporomandibular disorders (TMD) were evaluated with the Helkimo index (D 0-III) in a group of patients (n=105, F=69, M=36) after osteotomies. The average follow-up time was 47 months (9-141 months). The osteotomies performed were as follows: 58 bilateral sagittal split osteotomies, 12 Le Fort I osteotomies, 22 bimaxillary osteotomies, and 13 segment-osteotomies. A control group (n=202, F=114, M=88, age 20-39 years) was examined in an epidemiological study. The statistical analysis was performed using Windows software SPSS 10.0. RESULT: In 82.8% of the patients no symptoms or mild dysfunction were found. The comparison between the patient group (31.4%) and the control group (31.7%) revealed a similar frequency. The most frequent dysfunction was a reduced mobility of the mandible, which determined the statistical significance (p<0,05) between the patients and the control group for the dysfunction group D II and D III. The chi-square test could not detect any difference between sex and the kind of osteotomy with regard to dysfunction.

Adult↗

[Surgical techniques in renal transplantation].

Surgical techniques in renal transplantation are standardized and have remained basically unchanged for the last 50 years. A limited pool of donor organs is still an unsolved problem. Therefore, marginal organs are also used. Sophisticated techniques are used in children and in cases with vascular problems or complications. Laparoscopic techniques are emerging in renal transplantation. The article provides an overview on current technical standards of renal transplantation and potential surgical and urological complications. We report the results of our own renal transplantation program with special emphasis on vascular techniques, pediatric transplantation, and the management of complications. Special case reports are included.

Adult↗

[Follow-up in kidney transplantation. Which complications are likely?].

Kidney transplantations are being performed in every increasing numbers, and, in addition to specialist centres, nephrologists, general practitioners and urologists are more frequently being involved in the provision of aftercare. The major urological complications seen after transplantation include ureteral stenosis and necrosis, incontinence and impotence, lymphoceles, arterial stenosis, infections of the urinary tract and adnexa, as well as--the most serious complication--malignant tumours. In addition, the immunosuppression required by these patients is often associated with secondary disorders such as hypertension, steroid-related diabetes, hyperlipidemia and infections. Against the background of progressive organic deficiency it is of particular importance to identify such complications and to treat them adequately, or to prevent them from occurring, thus ensuring the longest possible survival of transplant and patient and improved quality of life.

Aftercare↗

Frequent genetic alterations in flat urothelial hyperplasias and concomitant papillary bladder cancer as detected by CGH, LOH, and FISH analyses.

Flat urothelial hyperplasia, defined as markedly thickened urothelium without cytological atypia, is regarded in the new WHO classification as a urothelial lesion without malignant potential. Frequent deletions of chromosome 9 detected by fluorescence in situ hybridization (FISH) have been previously reported in flat urothelial hyperplasias found in patients with papillary bladder cancer. Using comparative genomic hybridization (CGH) and microsatellite analysis, these hyperplasias and concomitant papillary tumours of the same patients were screened for other genetic alterations to validate and extend the previous findings. Eleven flat hyperplasias detected by 5-ALA-induced fluorescence endoscopy and ten papillary urothelial carcinomas (pTaG1-G2) from ten patients were investigated. After microdissection, the DNA of the lesions was pre-amplified using whole genome amplification (I-PEP-PCR). Loss of heterozygosity (LOH) analyses were performed with five microsatellite markers at chromosomes 9p, 9q, and 17p. CGH was performed using standard protocols. In 6 of 11 hyperplasias and 7 of 10 papillary tumours, deletions at chromosome 9 were simultaneously shown by FISH, LOH, and CGH analyses. There was a good correlation between FISH, LOH, and CGH analyses, with identical results in 6 of 10 patients. In addition to deletions at chromosome 9, further genetic alterations were detected by CGH in 9 of 10 investigated hyperplasias, including changes frequently found in invasive papillary bladder cancer (loss of chromosomes 2q, 4, 8p, and 11p; gain of chromosome 17; and amplification at 11q12q13). There was considerable genetic heterogeneity between hyperplasias and papillary tumours, but a clonal relationship was suggested by LOH and/or CGH analyses in 5 of 10 cases. These data support the hypothesis that flat urothelial hyperplasias can display many genetic alterations commonly found in bladder cancer and could therefore be an early neoplastic lesion in the multistep development of invasive urothelial carcinoma.

Aged↗

Angina intensity is not different in diabetic and non-diabetic patients with acute myocardial infarction.

BACKGROUND: Diabetic patients with acute myocardial infarction (AMI) may have diminished pain or a higher frequency of asymptomatic infarctions. This appears to be a common clinical perception. METHODS: Data from two registries of AMI patients presenting in hospital (MITRA PLUS with 18786 patients; North German Registry, NGR, 1042 patients with detailed symptom interviews) were analyzed concerning symptoms of acute myocardial infarction in patients with diabetes mellitus (DM) and without diabetes (non-DM). RESULTS: DM patients were significantly older and more often female than non-DM. There were no differences in the frequency of pre-infarction angina between DM and non-DM (Mitra Plus). In NGR, severe angina during AMI occurred in 49.8% of DM and 46.3% of non-DM (n. s.). No chest pain was reported in 16.9% of DM and 15.0% of non-DM (n. s.). Extra-thoracic pain, dizziness, nausea, sweating, palpitations, radiation of angina and localization of radiating pain was not different between DM and non-DM patients. Severe dyspnea occurred in 29.5% of DM and 19.5% of non-DM patients (p = 0.003). CONCLUSIONS: Apart from a higher frequency of severe dyspnea in diabetics, there appears to be no difference in the clinical symptoms of AMI patients with and without diabetes mellitus. AMI with little or no angina was also frequently found in non-diabetics. In the hospital, diabetics with suspected AMI do not appear to need a special judgement of symptoms. This could accelerate access of diabetics to standard therapeutic procedures.

Aged↗

[Perioperative antibiotic prophylaxis in transperitoneal tumor nephrectomy: does it lower the rate of clinically significant postoperative infections?].

This monocentric prospective randomized study was designed to determine the efficacy of single-shot perioperative antibiotic prophylaxis with 1 g ceftriaxone i.v. in transperitoneal tumor nephrectomy. Eighty-three patients were randomized either into a prophylaxis or a control group: 39 patients received 1 g ceftriaxone i.v. 30 min preoperatively and 44 no study medication. Characteristics of the two groups showed no statistical differences. Postoperative overall infection rates were 7.7% and 27.3% (p=0.007), respectively. Postoperative assessment revealed overall 0 (0%)/7 (15.9%) wound infections, 0 (0%)/2 (4.5%) deep wound infections, 1 (2.6%)/2 (4.5%) pneumoniae, and 2 (5.2%)/3 (6.8%) significant urinary tract infections. In 4 (10.3%)/4 (9.1%) patients, postoperative antibiosis was started without detection of an infectious focus. Overall antibiotic treatment was carried out in 7 (17.9%)/12 (27.3%) patients postoperatively. Costs of antibiotic prophylaxis and/or treatment resulted in 23.60/30.10ZZZ;EUR per patient. Perioperative prophylaxis with 1 g ceftriaxone i.v. decreases postoperative infection rates. Although not all infections have to be treated with antibiotics, there are pharmacoeconomic advantages of such prophylaxis.

Anti-Bacterial Agents↗

Ex vivo stimulation of renal transport of the cytostatic drugs methotrexate, cisplatin, topotecan (Hycamtin) and raltitrexed (Tomudex) by dexamethasone, T3 and EGF in intact human and rat kidney tissue and in human renal cell carcinoma.

Previous experiments have shown that both in vivo and in vitro pre-treatment with various hormones increases the renal transport capacity for weak organic acids, such as PAH, in rats. The aim of the present study was to test whether or not accumulation of the anticancer drugs methotrexate (MTX), cisplatin (CP), raltitrexed (Tomudex) and topotecan (Hycamtin) can be increased in intact, healthy rat and human renal cortical slices and in human renal cell carcinoma (RCC). Intact, healthy human tissue was obtained from tumour bearing kidneys of patients suffering from RCC. Experiments were intended as a new approach to overcome so-called multidrug resistance. Kidney tissue slices were incubated for 24 h in William's medium E containing various concentrations of dexamethasone, T(3), or EGF. Thereafter slices were placed in anticancer drug containing Cross-Taggart medium and the drug uptake into kidney tissue was measured for 2 h. In intact rat and human renal tissue slices, the uptake of p-aminohippurate (PAH = reference substance) increased significantly after incubation in dexamethasone containing medium (134% and 156%, respectively). There were no stimulating effects of either T(3) or EGF on PAH accumulation. On the other hand, only the accumulation of MTX, but not of CP, raltitrexed or topotecan, was significantly enhanced after hormone pre-treatment both in intact renal tissue and in RCC. A stimulation of renal PAH accumulation can be performed ex vivo, as reported previously, both in intact rat and human renal cortical slices and in RCC. Discrepancies between the effects of dexamethasone and T(3) or EGF indicate different modes of action of these substances at the cellular level. Unfortunately, with the exception of MTX, the uptake of anticancer drugs can not be stimulated effectively ex vivo in human RCC tissue by the substances used. Evidently the transport of these anticancer drugs out of the kidney cells is more effective than their uptake.

Animals↗

[Kidney transplantation in the elderly].

As the number of both elderly patients suffering from end-stage renal disease and of elderly donors is increasing, Eurotransplant has started the Eurotransplant Senior Program (ESP). New strategies for treatment of patients who need dialysis and improved screening methods allow renal transplantation even in elderly patients. Improved immunosuppressive protocols for older recipients lead to higher patient survival rates and improved quality of life.

Aged↗

[Patient satisfaction with the outcome of surgical orthodontic intervention and effect of esthetic and functional criteria].

BACKGROUND: The aim of the study was to analyze the influence of possible temporary or permanent disorders of sensation on the degree of the patient's satisfaction following an orthognathic operation. PATIENTS AND METHODS: After an average of 47 months (range: 9-141), a follow-up examination was performed in 78 women (64.5%) and 43 men (35.5%) with an average age of 24.3 years (range: 19-40) at the time of operation. In 67 cases there had been a sagittal division of the mandible, in 11 cases a Le Fort I osteotomy, in 26 cases a bimaxillary osteotomy, in 4 cases an isolated genioplasty, and in 13 cases a segmental osteotomy in the upper or the lower jaw. In the peripheral area supplied by the nerves V2 and V3 sensation was examined by the two-point discrimination test and the result related to the patients' satisfaction using the chi-square test. RESULTS AND DISCUSSION: The following qualities of sensation were recorded: anesthetic (2.7%), hypesthetic (16.6%), paresthetic (8.3%), and normesthetic (72.4%). The patients' satisfaction was rated as very satisfied in 51.3%, as satisfactory in 44.8%, and in 3.9% the patients' expectations had not been fulfilled; 75% regarded their outward appearance as markedly improved and a good 50% of the patients noted improved mastication. Therefore, three-fourths of all the patients would even be willing to be operated on again. Two-dimensional analysis, however, demonstrated only a weakly significant positive relationship between patient satisfaction and the preserved, or restored, sensation in the trigeminal region.

Adult↗

[Furlow palatoplasty--experiences with 114 consecutive cases].

After introducing the Furlow's double opposing palatoplasty [4] in our clinic in 1991 114 patients were operated on and registered prospectively. Using this procedure for closure of small clefts and/or with moderate velopharyngeal incompetence only at the beginning it became the method of choice not only for primary palatoplasty at the age of 18-24 months but also for corrective measures now. An increase of length of the soft palate of 10 +/- 3 mm at the average was gained immediately after surgery. There were no specific side effects of the method, especially no fistulas occurred. Good speech results were obtained in 61% at the age of 8 years using profound phoniatric tests. Mixed velopharyngeal closure investigated by means of nasal videoscopy was the dominating form in 55%. The results underwent a positive change comparing results in patients after longitudinal investigation at the age of 5 and 8 years bzw. They corresponded with or exceeded the results found in a control group operated on with other methods of palatoplasty at another centre.

Child↗

[The FAMI screw for temporary intermaxillary fixation. Report of experiences for extending indications].

The aim of this study was to demonstrate the suitability of the FAMI screw (fixation and adaptation in mandibular injuries) for maxillomandibular fixation in the maxillofacial area in orthognathic and trauma surgery. This FAMI screw was used in 28 patients for maxillomandibular fixation with wiring or elastics. The screw is inserted into the labial or buccal surfaces of the alveolar process without predrilling. Adequate intermaxillary fixation with balanced occlusion was created intraoperatively in all patients. In comparison with conventional splinting methods, this technique was far less time-consuming. The use of the FAMI screw has the advantage of being quick and simple, particularly if only a brief period of maxillomandibular immobilization is planned. Furthermore, the risk to the surgeon of sustaining a puncture injury from wire ligatures is distinctly reduced. Screws can be removed without local anesthesia. The above-mentioned method is minimally traumatic, effective, timesaving, and hence inexpensive. It can be used for maxillomandibular immobilization in dentate as well as in edentulous patients.

Bone Screws↗